Natural Heritage Management

Montane Scrub

MONTANESCRUB

ACTIONGROUP

MONTANESCRUB

ACTIONGROUP

SCOTTISHNATURALHERITAGE

Scottish Natural Heritage 2000

ISBN 1 85397 103 0

A CIP record is held at the British Library

L2K1100

Acknowledgements

Authors: Michael Scott for the Montane Scrub Action Group

This booklet is an output from the Montane Scrub Restoration Project part of the Millennium Forest for Scotland

managed by Highland Birchwoods, and has been endorsed by the Royal Society for the Protection of Birds.

Photography:

D. Bell/Ecos 22, M.Biancarelli/Woodfall Wild Images 15 bottom right, L.Campbell front cover

bottom right, 13, 15 bottom left, A. Hester front cover left, 2 bottom, 20, 31right, D.Gilbert 19 centre,

L.Gill frontspiece, 2 top, 4 top, 4 centre, 4 bottom, 7 top, 7 bottom, 8 top, 8 bottom left, 8 bottom right, 9

top, 9 bottom, 10 top, 10 bottom, 11 top left, 11 top centre, 16 top, 16 bottom, 19 top, 23 bottom, 27,

31 left, D.K. Mardon front cover top right, 12, 14, 15 top right, 17, 21 top, 21 bottom, 23 top, 24, 25

top, 25 bottom, 29 left, 29 right, 30, R.Parks 11 top right, K.Ringland 15 top left, R.Soutar 19 bottom,

M.Scott 3, 6, 26 top, 26 bottom, 28.

Illustration:

C.Hewitt

Further copies of this booklet and other publications can be obtained from:

The Publications Section,

Scottish Natural Heritage,

Battleby, Redgorton,

Perth PH1 3EW

Tel: 01783 444177 Fax: 01783 827411

Cover images:

Craig Fhiaclach (left), net-leaved willow (top right), black grouse (bottom right).

Back page image:

Cliff flora with net-leaved willow, Ben Lawers.

MONTANE SCRUBPreasarnach na beinne

Over the last 15 years we have reversed the threat to our native forestsand woodlands and the process of restoration and expansion is wellunderway. However, at the upper margins of our forests, one woodlandtype, depleted more than most, has yet to be tackled. Remnants ofmontane scrub have hung on as trees or clumps of trees in exposedand remote locations, often protected from grazing animals by terrain.They are all that’s left of a once widespread zone between the forestand the open moorland.

These remnants are invariably cut off from the forests they once fringedand no longer function within an extensive ecosystem. The contortedshapes and diminutive habit that we associate with montane scrub isno accident. The trees survive in the most hostile conditions abovethe slopes where foresters have traditionally planted and regeneratedtrees. So the restoration will be a slow but rewarding process as adiffuse boundary evolves between forest and mountain.

The Forestry Commission’s role is to maximise the environmental andsocial benefits of forests as well as ensuring that they continue toproduce a flow of timber to support the rural economy. We have beenat the forefront of the restoration of Scotland’s native woodlands bothin our own forests managed by the Forest Enterprise and on landowned privately, supported through our Woodland Grant Scheme.

We enthusiastically support the current interest in treeline woodlands;they are an important element of the Forest Habitat Network approachwhich is a priority action in the Scottish Forestry Strategy. The restorationprocess will not always be easy, nor indeed achievable everywhere.However, where it can be done the rewards will be very visible andtangible. As the trees move up the hills they will not only enhance thislandscape and our natural forest biodiversity but will establish themissing element in our vision of a continuum of woodland cover fromthe river valleys to the biological limit of tree growth.

Sir Peter HutchisonChairmanForestry Commission

Foreword

Introduction 2What is montane scrub 3The loss of the ‘wee trees’ 7Plants of the scrub 10Wildlife in the scrub 13Restoring the landscape 17The woods and the trees 19

Shelter on the hill 21Game benefits 23Enjoying the hills 24Ecological values 25Action for scrub 27Bringing back the ‘wee trees’ 30Further reading 31

Contents

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That, however, overlooks the special qualities of montane scrub as anatural fringe to the forest. This booklet is a celebration of this forgottenmontane scrub habitat. It illustrates its value as a home or corridorfor plants and wildlife; as shelter for domestic stock and forestry; asa valuable resource in its own right; and as an attractive part ofScotland's natural heritage.

These gnarled, twisted trees - and the rich diversity of other plants andanimals associated with them - are not just a product of the tundraor the Alps. They once occurred on Scottish mountains as a naturalzone between woodlands and hilltop heaths. But this montane scrubhas almost disappeared from Scotland. In conservation terms, it isone of our most significant 'Cinderella' habitats.

In recent years, people have come to realise how much the naturalvegetation of the Scottish uplands has been impoverished by humanactivities. In response, an encouraging start has been made to restoringsome of the woodland that once covered the straths and glens andspread up the hillsides beyond. Whether for environmental ends orfor commercial forestry, most of this work has been driven by the desireto grow tall, straight trees. It has usually stopped at the altitude abovewhich foresters believe trees will not grow.

"The gnarly little trees were twisted as if cultivated byderanged bonsai gardeners...Thus the name krummholz,German for 'crooked wood' or perhaps 'elfin wood' - the zonewhere trees first managed to take advantage of the soil-building work of fellfields and alpine meadows. Treelimit."

(’Green Mars’, Kim Stanley Robinson)

Introduction

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Trees can grow in the most unpromising situations. Their roots spreadout to find nourishment and water, and act as an efficient anchor andprop, supporting the tree against the battering of gales. But no treescan grow near the tops of Scotland's highest mountains.

It is simply too windy and exposed, and the growing season is tooshort for trees to establish. A range of 'dwarf shrubs' are the only woodyplants that can survive at these altitudes. They include ling heather(Calluna vulgaris), crowberry (Empetrum nigrum), bilberry or blaeberry(Vaccinium myrtillus), bog bilberry (V. uliginosum) and other, morelocalised species.

What happens between the woodland zone on the lower slopes andthe dwarf shrubs high on the hill? It is wrong to imagine that there isa precise altitude at which tree growth is no longer possible and theforest simply ends. Trees can creep higher where a gully offers shelterthan they can on a wind-exposed hillside, so the upper margin of theforest is naturally 'feathered'. Straight upper edges of forests arise onlywhere fences to exclude grazing animals are constructed insensitively.

As trees approach their altitudinal limits, their growth is severelyretarded by long periods of low temperature. Pruning by icy windsmakes their branches grow outwards, rather than upwards. The resultis low-growing, crooked trees. Their twisted timber is of little value totraditional forest industries, so foresters avoid planting trees here.

Even at lower altitudes, the forest does not consist solely of tall foresttrees like sessile oak (Quercus petraea), downy birch (Betula pubescens)and Scots pine (Pinus sylvestris). Mixed with them are lower-growing,more shrubby species, such as rowan (Sorbus aucuparia), juniper(Juniperus communis) and willows (Salix species). As the high foresttrees begin to decline towards their altitudinal limit, these smallerspecies become more prevalent and eventually replace them completelyat altitudes above which the forest trees can no longer survive. Someshrubby species are high altitude specialists (see page 4), althoughseveral of these are now rare in Scotland.

This view from Sweden gives an impression of how some parts of theScottish hills might look if the first tentative steps to restore Scotland'smontane scrub can be successfully expanded to a larger scale.

What is montane scrub ?

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There is, therefore, a zonation up the hillside (see figure 1),although the gradation from one zone to the next is gradual,with indistinct boundaries. The forest zone is the extensivearea at low altitude in which trees grow tall and upright, andgenerally produce good timber.

At a particular altitude (which will vary with climate andexposure), trees can no longer maintain this upright growthform. That marks the timberline. Some trees may survive fora hundred metres or more above this altitude, but they growprogressively shorter and more twisted.

Continental botanists call this zone ‘krummholz’, which meansliterally 'twisted wood'. Then an altitude is reached at whichthe climate becomes so severe that even krummholz can nolonger survive. This is the treeline.

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Specialist montane scrub species

Dwarf juniper (Juniperus communis nana)Dwarf birch (Betula nana) *Montane willows:- Mountain willow (Salix arbuscula) *

Dwarf willow (S. herbacea)Woolly willow (S. lanata) **Downy willow (S. lapponum) *Dark-leaved willow (S. myrsinifolia)Whortle-leaved willow (S. myrsinites)*Tea-leaved willow (S. phylicifolia)

Net-leaved willow (S. reticulata) *

**rare ("Red Data Book") species

* scarce species

Figure 1: An idealised zonation up a mountain as the trees of theforest zone are replaced by low-growing scrub including stunted,twisted plants of Scots pine and then by dwarf shrubs on the high tops.A slightly different terminology is used on the continent (right handcolumn).

Legend:

Tree species (mainly Scots pine and birch)

Montane scrub species (mainly juniper and willows); In Scotland these can occur throughout the range, becomingpatchily dominant above the natural treeline.

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Above the treeline, montane scrub species may continue some distancefurther up the mountainside, but eventually they too die out, at thescrubline. Above this, only low-growing dwarf shrubs grow in montaneheath, although on the most exposed hills even these shrubs eventuallygive way on the windswept tops to a zone of mosses, lichens andsedges.

The tree and tall plant community between the timberline and thescrubline is the montane scrub zone to which this booklet is dedicated.

How high is the treeline?The altitude at which trees die out varies between species (Scots pines,for example, will grow higher up the hill than oaks), and with climate(the treeline is considerably lower in the more exposed north-west andon the islands). It was also higher during milder climatic periods in thepast. Today, Scots pine grows as high up the hills as any forest tree.At Creag Fhiaclach (see page 9), the pine treeline is almost 650 metres(2,100 feet) above sea level, although the timberline is 150 metres.

In the Krkonose (giant) Mountains of the Czech Republic, there is apronounced zone of montane scrub above the forest, but here themain species is the dwarf mountain pine (Pinus mugo), which doesnot grow more than 3.5 metres tall. In Scotland, its place is taken bylow-growing Scots pine and juniper.

On hillsides heavily grazed by deer or sheep, the only place where treeand scrub species can survive is on inaccessible cliffs and crags.(see also overleaf)

The loss of the ‘wee trees’

7

The decline of Scotland's native forests is well documented, but whydid the scrub above the woodland disappear? Natural changes in theclimate and soils undoubtedly contributed, and some scrub may havebeen collected for firewood or charcoal burning. However, the mainreason for the scrub's decline was browsing by domestic sheep, cattleand goats, and by red deer.

When farmers took their cattle and sheep to shielings high on the hillfor a few weeks each summer, the scrub, at first, must have providedvaluable shelter and browsing for their beasts, but the slow-growingscrub plants could not cope with heavy grazing, and their seedlingswere particularly palatable to grazing animals. So overgrazing destroyedthe mature bushes and blocked regeneration to replace them.

The last century in the Highlands saw huge increases in the numbersof red deer (Cervus elaphus), maintained and encouraged for sportshooting, and in hill sheep. Their combined grazing finally reducedthe surviving montane scrub to the tiny remnants that cling to a fewhills today.

The ancient survivors of Creag FhiaclachScotland's montane scrub has not quite disappeared entirely.A few tantalising remnants remain to hint at how this habitatmight once have looked, although nowhere are they asextensive or as varied as natural scrub must once have been.

Perhaps the most famous remnant is at Creag Fhiaclach onthe slopes of the Cairngorms. The natural timberline for Scotspine here is about 500 metres above sea-level. Above this,on a rocky, northwest-facing slope, pine continues to grow ataltitudes of up to 648 metres, where it forms what is believedto be the best natural pine treeline in Britain. It grows in a low,twisted 'krummholz' form, mixed with juniper scrub.

At this altitude, the trees are no more than two metres tall,although they often extend horizontally for at least this distance.Despite their small size, cores taken from their gnarled trunkshave shown them to be anything from 100 to 250 years old- real mountain survivors.

9

Some ancient, twisted pines survive 600 metres up on the slopes ofthe Cairngorms at Creag Fhiaclach.

Plants of the scrub

Because montane scrub has almost disappeared from Scotland, manyof the plants associated with it are also rare, including several of themontane willows. Woolly willow is so rare as to feature in the RedData Book of threatened plants (see box), and several other montanespecies listed on page 4 are officially recorded as scarce. Althoughjuniper is more widespread, it has declined greatly in parts of its rangeand is under severe management pressure elsewhere, with scarcelyany regeneration occurring at many of its sites. Both juniper andmountain willows are the subjects of Biodiversity Action Plans, publishedby the Government and the Scottish Executive, aimed at encouragingtheir conservation.

Woolly willow in troubleOf 14 populations of woolly willow known in 1996, just fivewere large enough to have any chance of surviving in thelong term. A survey showed that three of the other populationswere apparently extinct, and three had been reduced to justa single female plant. Like all willows, woolly willow grows asseparate male and female plants. It cannot reproduce unlessthe two sexes grow within about 50 metres of each other, toallow for effective pollination. It also needs bare ground, freefrom grazing, in which its seeds can germinate.

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Wood Cranesbill (top left)Globeflower (top middle)

Alpine Sowthistle (top right)Dwarf Birch (bottom)

Because the remaining montane scrub in Scotland consists of justscattered bushes, the ground flora associated with it is impoverishedor much suppressed. However, areas of 'subalpine scrub' on thecontinent give an idea of what the restored habitat in Scotland couldlook like. They often include attractive displays of wood cranesbill(Geranium sylvaticum), globeflower (Trollius europaeus) and a rangeof other 'tall herbs' which today are found in Scottish mountains onlyon inaccessible rock ledges.

The shelter and humidity also provide a habitat for ferns, mosses andlichens that otherwise would be restricted to shady gorges on thehillside.

One particularly attractive (and currently very rare) species that wouldbenefit from the restoration of montane scrub is alpine sowthistle(Cicerbita alpina). All the evidence suggests that in Scotland this wasonce a plant of high altitude birch woods, as it still is on the continent.

However, it is now on the very edge of extinction here because of thedrastic decline in these birchwoods and increased grazing by sheepand red deer. (It is a highly edible plant that is still eaten by the Samipeople of northern Scandinavia, as 'Lapp Lettuce').

Today this tall, spectacular plant is confined to just four sites in theHighlands, on rock ledges beyond the reach of hungry deer andsheep. Through its Species Action Programme, Scottish Natural Heritageis working to protect the plant, but only a significant restoration of itsmontane scrub habitat will secure the sowthistle's future.

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Whortle-leaved willow

Wildlife in the scrub

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Many birds stand to benefit from the restoration of montane scrub.A range of thrushes and finches would be at home in the scrub. Itwould also be valuable for migrants, especially in autumn when fruitsand seeds would provide a refuelling stop for them on their journeyssouth. The scrub might encourage more breeding in Scotland byredwings (Turdus iliacus), fieldfares (T. pilaris) and bramblings (Fringillamontifringilla), which at present nest here scarcely or sporadically. Itmay even encourage colonisation by other Scandinavian woodlandand scrub species, such as bluethroats (Luscinia svecica) and Laplandbuntings (Calcarius lapponicus). The scrub would not hinder goldeneagles, buzzards or other birds of prey, which still could hunt amongstthe sparse shrubs and might benefit from an increase in small mammaland bird prey.

Black grouse (Tetrao tetrix) are birds of the forest edge. They shelterin the forest, but move into open areas for their spectacular breedingdisplays, called leks. They feed on plant material both in the forestand outside it.

They are currently in serious decline across Scotland, but should benefitfrom an increase in montane scrub. However, any essential fenceswould need to be carefully sited and well marked, because collisionswith deer fences are one of the main causes of death in adult blackgrouse.

A spread of montane scrub would increase numbers of voles, miceand shrews, which would, in turn, help the foxes, stoats and pinemartens that hunt them. Mountain hares (Lepus timidus) are moreproblematic. Large winter gatherings of hares could cause localiseddamage to scrub regeneration, and hares might need to be discouragedor excluded while the scrub is establishing. Deer and sheep wouldalso need to be kept away from regenerating scrub. However, in time,the natural re-establishment of montane scrub would be a potentindicator that deer had been brought into sustainable balance withtheir range - one of the main objectives of current deer managementpolicies.

Golden Eagle

A number of specialised invertebrates are associated with montanescrub species. At least six species of sawflies in the genus Potaniamake 'cherry-galls' on the leaves of montane willows, including twospecies that are only known from Scotland. An attractive 'micro-moth',called Callisto coffeella, is found in Scotland only on isolated bushesof dark-leaved willow on north-facing slopes in the Angus andAberdeenshire glens. Several aphids and moths are associatedparticularly with dwarf birch, and about thirty species of insects andmites are exclusive to juniper.

The value of montane scrub for biodiversity is recognised by the RoyalSociety for the Protection of Birds. Its Abernethy Reserve in Strathspeyextends almost to the summit of Cairn Gorm, and one of the long-term management objectives of the reserve is the expansion ofCaledonian forest up to the treeline, with a natural scrub zone beyond.

A pair of Leaf Beetles on mountain willows

Montane scrub wildlife: Fieldfare (top left) and bluethroats (bottom right)might be encouraged to nest in montane scrub in Scotland. Insects likethe caterpillar of the puss moth (top right) would also breed in the scrub,although mountain hares (bottom left) might need to be excluded to allowthe scrub to establish.

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The Creag Meagaidh ExperimentSince its purchase by the former Nature Conservancy Council (now SNH)in 1985, and its establishment as a National Nature Reserve, a greatexperiment in woodland restoration has been underway at CreagMeagaidh, on the north shore of Loch Laggan in Inverness-shire.

The reserve includes high elevation woods of downy birch, goat willow(Salix caprea) and rowan, but at the time of purchase most of these weremoribund as a result of intensive grazing. The regeneration and extensionof native woodland and montane scrub was one of the key objectivesfor the reserve.

This has been achieved with minimal use of fencing. Instead, managementhas aimed to exclude sheep as far as practicable, and large numbersof red deer have been culled or removed from the reserve (without impacton neighbouring deer-stalking estates). The results have been spectacular,with a sevenfold increase in downy birch regeneration, and healthy rowanand willow growth. Although recovery has been best on the lower slopes,there are encouraging signs of scrub development above the timberline,providing a pointer to what could be achieved elsewhere.

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Scrub regeneration on the upper slopes of Creag Meagaidh.

Where montane scrub hangs on in a few high-altitude corries, or inareas of steep and broken ground, it is generally so sparse andrestricted as to have no visual impact on the landscape. Improvingits condition and extent will diversify the scenery, adding to its visualqualities and bringing a stronger sense of seasonality, as the deciduousspecies change colour from spring through to autumn.

Other than on nature reserves, large-scale restoration of montanescrub is likely to be viable only on the upper margins of existing forestryschemes, and here it could have an especially valuable role in thelandscape.

In the last 50 years, several millennia of deforestation have beenreversed in Scotland. The Forestry Commission estimated in 1998 thatScotland had some 1,109,000 hectares (4,280 square miles) of'productive woodlands' and 93,000 hectares of other (mainly amenity)woodland. In the rush to establish a strategic timber crop after theSecond World War, many early plantations were planted with littlethought for the landscape. Today, however, the best plantations followdetailed landscape guidelines developed by the Forestry Commissionto protect the scenery that is such a major Scottish asset.

Because grant-aid for forestry is derived for a system which originallyhad the sole aim of boosting wood production, even native woodlandschemes tend to stop at or below the timberline. This inevitably resultsin a sharp cut-off at the upper margin of the forest, which can bemitigated only partly by landscaping. Just as the most magnificentcurtains look inadequate without an elegant pelmet to set them off,so hill forests also need 'topping off'. That is a key role for montanescrub. It softens the hard and unnatural edges of plantations, andallows for a gentle gradation between the forest and the montaneheath, both visually and ecologically.

Short term fencing is likely to be essential in most montane scrubrestoration schemes to exclude grazing animals while the plantsestablish. Careful guidelines will be needed for the siting, design andconstruction of these fences. The aim should be to site them asunobtrusively as the terrain allows, without blocking recreationalaccess. They should be removed as soon as the scrub is well establishedand browsing has been brought into balance.

Restoring the landscape

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With no large areas of montane scrub in Scotland, we need to look toareas like western Norway to get an impression of its role in the landscape.

Figure 2: A heavily grazed and uniformlandscape (top) can be diversified by well-designed forestry (middle), but the additionof a montane scrub zone (bottom) softensthe visual impact of the forest and createsa more natural 'feel' to the landscape.

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The wood and the trees

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Without shelter, trees planted at or near the timberline are highlysusceptible to wind damage. Even if gales do not blow them over,their growth will be severely retarded by exposure. Because of this,many forest plantations stop below the theoretical limit for tree growth.

However, montane scrub that is planted or encouraged above aplantation can provide valuable shelter. It streamlines the upper marginsof the forest so that winds sweep over the trees. This helps to protectthe trees from 'windthrow' and encourages better growth by reducingexposure. In turn, this may allow productive forestry to be extendedright up to the commercial timberline, at relatively little cost in extraland and fencing.

Montane scrub can soften the visual effect of a stark timberline and protectthe trees on the upper margins of the forest. (top and middle)

Without shelter, high-elevation plantations are highly susceptible to'windthrow'. (bottom)

The wood from the stunted trees and low-growing shrubs of themontane zone will be of no value to traditional timber industries.However, high-value craft industries might be able to use thegnarled shape and contorted grain of some 'krummholz' wood togood artistic effect.

Other products from the scrub may also be of value in craft industries- for example dyes from lichens - while some scrub material couldalso be used for thatching. However any extraction would need to berestrained because of the slow growth of scrub.

Montane scrub, therefore, offers a new opportunity for the forestindustry, providing a legitimate use for land that is unsuitable otherwisefor commercial tree crops. However, its establishment or restorationis only ever likely to be commercially feasible if it is incorporatedinto the management of existing forests or into new native woodlandor forestry schemes, where little additional fencing would be required.Even so, such schemes are unlikely to be fully viable without grant aid.

This has been recognised by the Forestry Commission. Its 1998Guidance Note, Treeline Woodlands and the Woodland Grant Scheme,affirms that the Commission will make funding available in certaincircumstances, through the Woodland Grant Scheme, to support theexpansion of woodland and scrub above the commercial timberline.The incorporation of montane scrub into Woodland Grant Schemesand Forest Design Plans represents an exciting and cost-effective wayto conserve and expand this 'Cinderella' habitat.

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The twisted shapes of wood from montane scrub can provide artisticinspiration to craft workers.

Shelter on the hill

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Ultimately, the main drive for the restoration of montane scrub is likelyalways to be the aesthetic vision of restoring Scotland to its fullecological potential. Landscape benefits and forest shelter are addedvalues from the restored habitat. How should the farmer view thispotential competing use for hill pasture?

Montane (or high altitude) scrub is likely to be considered only on theleast accessible and least productive parts of a hill farm. It is thereforeunlikely to force any reduction in stock numbers, especially at a timewhen subsidy schemes are already being modified to reduce grazingdensities. Stock will need to be excluded from montane scrub duringits establishment, and even mature scrub will not survive high grazingpressure. However, areas of scrub within an extensive hill pasturecould provide valuable shelter for stock on the hill during severespring and summer weather. Protection from exposure and heat losscould be especially valuable for lactating ewes in spring - when'lambing snows' seem an all too regular occurrence. This benefit couldincrease if human-induced climate change brings more 'extremeweather events', as many scientists predict.

Scrub would provide valuable shelter for sheep in severe weather (top)compared to the open hill (below), although it would also make themmore difficult to gather.

Montane scrub would somewhat increase the forage available tograzing animals. The shade from the scrub would tend to excludegrass species of low nutritive value, such as mat grass (Nardus stricta),and encourage shade-tolerant species, which generally have a higherdigestibility for herbivores. By holding winter snows for longer, thescrub would also improve soil moisture regimes, compared to openhillsides, and this would further enhance the grazing for small numbersof stock.

There is a potential downside to this picture. Scrub could make itmore difficult and time-consuming to gather sheep for shearing ordipping. Furthermore, the benefits that would accrue from shelter andimproved grazing would be unlikely to compensate fully for the initialcost of excluding stock while the scrub establishes.

Grants under the Woodland Grant Scheme might reduce thesedisbenefits for any farmer who wanted to contribute to the vision ofrestoring Scotland's natural environments. Within Sites of SpecialScientific Interest, positive management grants may be available fromScottish Natural Heritage for such work, and future environmentalsubsidy schemes for agriculture might also offer support for montanescrub restoration.

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On sporting estates, well-designed restoration and expansion ofmontane scrub would be unlikely to have significant negative effectson game stocks, and some game species would benefit directly froman increase in habitat. One particularly important species that mightbenefit is the black grouse. Its numbers are currently in such seriousdecline, as a result of loss of habitat and collisions with deer fences,that it is no longer hunted on any significant scale. The improvedgrazing and shelter would also increase the carrying capacity of theland for red deer.

Some estate owners express concern about a perceived conflict betweenthe recreational use of hill land and field sports, particularly deerstalking. They argue that conspicuously-clad walkers disturb deerduring calving and make them more difficult to stalk, either for sportor population management. Whatever the true scale of this impact,it could be reduced significantly by an expansion of montane scrub.Walkers would be somewhat less visible whilst amongst the scrub, andthe additional cover would make deer much less susceptible todisturbance.

Game benefits

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Montane scrub would provide new habital for the black grouse (top) andadditional cover for red deer, making them less susceptible to disturbanceby walkers.

Enjoying the hills

Most hillwalkers will welcome the more natural appearance of hillsideswith limited areas of montane scrub cover. There is unlikely to be anymanagement conflict between their needs and the requirements forscrub restoration because walkers tend to follow ridges where scrubdevelopment will be limited by exposure.

Care will need to be taken to site scrub areas and temporary fencesso that they are not visually intrusive and do not obstruct passage,although this can be overcome by providing stiles and gates (whichmay be funded within the Woodland Grant Scheme). In the longerterm, montane scrub could channel visitors unobtrusively, helping toreduce erosion beside paths. It could also provide some shelter fromthe elements, which is likely to be appreciated by all but the most'Spartan' of tastes.

Even skiing will not be seriously impeded by montane scrub, becausevery little of it is likely to become established in popular skiing areas.Even if it does, scattered scrub will not present a serious obstacle, andmay improve the snow-holding characteristics of slopes.

Montane scrub could enhance the experience for walkers in the hills,providing shelter and creating a more appealing landscape.

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In the relatively extreme situation of high altitudes, montane scrub canhave a valuable protection role. By establishing greater shelter anddeeper, more robust root systems, it helps to prevent erosion, especiallyon hillsides which have suffered from heavy grazing in the past. It canalso reduce leaching (the process by which rain washes minerals andnutrients deep down into the soil or into streams, so that surface soilsbecome progressively more impoverished). The roots of the shrubsdraw goodness from the soil and return it to the soil surface in theirleaf litter, helping to maintain the natural nutrient capital of the soil.

The humid substrate established beneath the scrub canopy absorbsrainfall during wet periods, thus contributing to reduced run-off andlessening the risk of flooding downstream. It then releases this watergradually, helping to maintain river flows and reduce the likelihoodof drought in dry conditions. The leaf litter beneath the scrub mightslow the release of atmospheric pollution into burns, to the benefit ofsensitive vegetation downstream.

Perhaps most importantly, as this booklet has shown, montane scrubrepresents a natural zone of transition between woodland in the strathsand montane heaths higher on the hill.

At the 'Earth Summit' in Rio de Janeiro in 1992, Britain signed theConvention on Biological Diversity. Biological diversity - or 'biodiversity'for short - is defined as "the total diversity and variability of livingthings, and of the systems of which they are part". The principles ofbiodiversity therefore require the protection of natural habitats andprocesses, as well as species. The restoration of montane scrub is thusa vital part of the reinstatement of natural patterns and processes inthe Scottish hills.

Montane scrub can help toregulate water flow from themountains, reducing the risk offloods and drought.

Ecological values

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The Cairn Gorm ‘Krummholz’In the Northern Corries of Cairn Gorm, a substantial colonisationof low, twisted pines, with occasional juniper, rowan and birchbushes, has developed at an altitude of between 450 and850 metres. This seems to have begun following the cessationof burning and very substantial deer culls in the area in themid-1940s. The fencing of large areas of lower ground forforestry has greatly reduced the use of the Northern Corriesby deer, and the increase in human activity following the skidevelopments at Coire Cas also discourages deer, especiallyduring winter when the scrub is most likely to be grazed. Ifbrowsing pressure remains low, this may lead eventually to theestablishment of montane pine scrub, but the other scrubspecies will remain depleted, at least for the next century orso, unless there is active intervention to aid their spread.

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Where no remnant scrub remains, restoration may require collection oflocal seed for propagation and planting in appropriate locations.

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Montane scrub sometimes survives as just a few bushes clinging to acliff ledge, beyond the reach of sheep or deer. As long as these plantsare close enough for pollination, their seeds can be carried substantialdistances by birds or the wind. The scrub, therefore, has some capacityfor natural regeneration, provided other conditions are right. Forexample, in a few areas where plantation fences have impeded themovements of deer, open patches of scrub have begun to return toungrazed areas above the fenceline.

However, the future for montane scrub is bleak without positivemeasures for its conservation. A major seminar held in 1996, as partof a Millennium Forest for Scotland project, stimulated interest in theecology and restoration of montane scrub habitats in Scotland. Otherinitiatives are underway, including surveys of surviving scrub and anumber of experimental grazing exclosures to encourage scrubregeneration.

Action for scrub

As part of its Millennium Forest for Scotland project, HighlandBirchwoods has established several demonstration montane scrubplanting schemes, including this one in Wester Ross.

Scottish Natural Heritage and the Montane Scrub Action Group(see page 31) are masterminding measures to encourage the restorationof montane scrub. There is great opportunity for other land holdersand land managers to contribute towards this vision of restoringScotland's hills to their former glory.

The Ben Lawers visionBy the 1980s, only two female plants of woolly willow survived in the Ben Lawers National Nature Reserve in Perthshire. They were 10kilometres apart and at least as far from the nearest male of the species. Not surprisingly, they did not produce seeds. Other montanewillows and juniper were also at critically low densities. In 1989 and 1990, two grazing exclosures were established on land owned bythe National Trust for Scotland (NTS). Considerable natural regeneration has occurred within the exclosures, enhanced by planting outplants of the rarer species propagated from surviving specimens in the reserve. Although these plants are still young, parts of the exclosuresare already acquiring a 'natural' scrub appearance.

In 1996, the NTS bought Meall nan Tarmachan, adjoining its Ben Lawers property to the west. Here it has even more ambitious plans toestablish a 167-hectare exclosure within 5.5 kilometres of electric fence at Creag an Lochain. The NTS proposes to plant birch, downywillow and other species in the exclosure, although it may take another 50 years to realise the exciting vision of extensively restored montanewillow scrub.

29

The Creag an Lochain cliffs, where the National Trust for Scotlandproposes the extensive restoration of montane scrub.

Some of the montane scrub being established within large exclosures,accessible to visitors, in the Ben Lawers National Nature Reserve.

Bringing back the ‘wee trees’

The Forestry Commission Guidance Note, Treeline Woodlands andthe Woodland Grant Scheme states: "It is now widely accepted thatextending woodland cover 'up the hill' enhances biodiversity and cancreate a softer visual boundary between forest and open hill. Inencouraging treeline woodlands in Scotland, the aim is to create acontinuum of woodland cover which reflects climatic and edaphic(ie, soil) gradients from the valley floor to the biological limit of treegrowth (the treeline)."

This is a considerable vision, for which the Forestry Commissiondeserves great credit, but it will not be achieved without far-sightedlandowners who wish to make their own contribution towards realisingthis vision. By taking advantage of the available grants to pioneerrestoration projects on their land, they can create examples whichother landowners may wish to follow. The task is not easy becausethere is much still to learn on the best techniques for establishingscrub, but the potential benefits in restoring the uplands of Scotlandto their full ecological potential and diversity are immense.

Montane scrub will provide a valuable feature for the landscape,for the environment, and, above all, for people.

30

The Montane Scrub Action GroupThe highest priority is to protect and restore the remnants of montane scrub that survive. That is a key task identified by the MontaneScrub Action Group, set up after a seminar on Montane Scrub in 1996. It is working to promote the importance of this habitat (throughinitiatives such as this booklet), while several members of the group, including the Scottish Agricultural College and Highland Birchwoods,are carrying out their own experimental projects on montane scrub restoration.

There is much to learn about how to propagate material for new planting, how to prepare the ground to encourage the establishmentof montane scrub with minimum disruption of the natural ecosystem, and how to erect fences that exclude grazers without impacting onwoodland grouse, the landscape and recreational access. Identifying 'best practice' in these techniques is another key task for the group.

The group publishes an occasional newsletter, Scrubbers' Bulletin, aimed at keeping informed all those actively involved in montanescrub studies and projects. Further details of the group are available from:

Montane Scrub Action Groupc/o Highland BirchwoodsLittleburn, MunlochyRoss-shire IV8 8NN(SAE appreciated).

The treeline zone in most of the Scottish uplands today is represented by just a few shrubs and trees clinging to isolated cliffs (above left). Butforesight and dedication can deliver a vision of extensively restored montane scrub from existing remnants, similar to what we see today, forexample, in Craig Fiaclach (top right).

31

Forestry Commission (1998). Treeline Woodland & the Woodland Grant Scheme.Forestry Commission (National Office, Scotland), Edinburgh

Gilbert, D, Horsefield, D and Thompson, DBA (1997) The ecology and restorationof montane and sub-alpine scrub habitats in Scotland. (Scottish Natural HeritageReview no.83).

Horsfield, D and Thompson DBA (1996) The uplands: guidance on terminologyregarding altitudinal zonation and related terms (SNH Information and AdvisoryNote No 26).

MacKenzie N A (2000) Low alpine, subalpine and coastal scrub communities inScotland (Highland Birchwoods)

Ramsay, Paul (1996). Revival of the land: Creag Meagaidh National NatureReserve. (Scottish Natural Heritage)

Further reading

32

SNH Publications Order Form:Natural Heritage Management series

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Car Parks in the Countryside: A PracticalGuide to Planning, Design and Construction £9.99

Upland Pathwork:Construction Standards for Scotland £15.00

Minerals and the Natural Heritage inScotland’s Midland Valley £9.99

A Technical Guide to the Design andConstruction of Lowland Recreation Routes £7.99

Management of Roadside Vergesfor Nature Conservation FREE

Field Guide to Upland Habitats: SurveyingLand Management Impacts £30.00

Natural heritage Zones: Planning the WiseUse of Scotland’s Natural Diversity FREE

Biogeographic Zonation of Scotland FREE

TIBRE Handbook FREE

Sustainable Development and the NaturalHeritage: The SNH Approach FREE

The Natural Heritage In and Around Settlements FREE

Report of the UK Raptor Working Group £9.99

Sustainable Feeding of Hen Harriers on GrouseMoorlands: A Practical Guide FREE

Good Practice for Grouse Moor Management FREE

The Design and Construction of Bat Boxesin Houses FREE

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Bogs: The Ecology, Classification andConservation of Ombrotrophic Mires £5.00

Research, Survey and MonitoringReports and Reviews Series

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Car Parks in the Countryside:

A Practical Guide to planning,

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Minerals and the Natural Heritage

in Scotland’s Midland ValleyMinerals extraction has, arguably, the greatest

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A Technical Guide to the Design and

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ISBN 1 85397 024 7 pbk 28pp £2.50

Field Guide to Upland Habitats:

Surveying Land Management ImpactsFor decades there have been debates about the ‘state’ of the uplands

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ISBN 1 85397 296 7

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Report of the UK Raptor Working GroupThis report by the UK Raptor Working Group considers the perceived

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Bogs: The Ecology, Classification and

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ISBN 1 85397 100 6 £5.00

MACAULAYLAND USERESEARCHINSTITUTE

The Montane Scrub Action Group is an informalinter-disciplinary partnership of individuals, supported byorganisations, actively promoting the benefits and restorationof semi-natural montane scrub.

Montane scrub, that fascinating mix of gnarled and twisted 'wee trees' and other plants and animals associatedwith them, is the 'Cinderella' habitat of Scotland. Without positive measures for reinstatement, the future forthis valuable habitat looks bleak. Forming a natural zone between the treeline and the high montane heath,montane scrub adds diversity to the scenery, helps to prevent erosion, and provides a haven for nesting birdsand a valuable food source for migrants.

This beautifully illustrated book outlines the steps the Montane Scrub Action Group is taking to restore Scotland'shills to their former glory.

Scottish Natural Heritage is a government body responsible tothe Scottish Executive and Scottish Parliament.

Our mission statement: Working with Scotland's people to carefor our natural heritage.

Our aim: Scotland's natural heritage is a local, national andglobal asset. We promote its care and improvement, its responsibleenjoyment, its greater understanding and appreciation and itssustainable use now and for future generations.

ISBN 1 85397 103 0

Price £3.95Scottish Natural Heritage

Visit our website on http://www.snh.org.uk

9 781853 971037

ISBN 1-85397-103-0