National Character Area 110

Chilterns - Analysis: Landscape Attributes & Opportunities

Analysis supporting Statements of Environmental Opportunity

The following analysis section focuses on the landscape attributes and opportunities for this NCA.

Further analysis on ecosytem services for this NCA is contained in the Analysis: Ecosytem Services section.

Landscape attributes

Chalk and periglacial landforms and features, including a prominent escarpment and dry valleys.

Justification for selection:

  • Adjacent to the clay vales, the Chalk escarpment is an abrupt change in elevation, 300 m above the Vale of Aylesbury. It stands as a distinctive relief feature visible from miles around. Extensive views are provided by the ridge, particularly from open downland.
  • The views and experiences across this landscape are variable, as a result, in part, of landform. The enclosed nature of small valleys contrasts with the extensive views and open landscape on parts of the scarp and ridges.
  • The crest line of the escarpment becomes progressively lower towards Hertfordshire, in the north-east, where it was overridden by ice sheets during the Anglian glaciation.
  • Exposed Chalk is infrequent and woodland cover is extensive; however, the underlying bedrock is made prominent by the few local landmark carved figures, for example Whiteleaf Cross. The few Chalk exposures provide access to key Cretaceous sequences and yields important fossils.
  • The numerous valleys across the dip slope create topography of alternating ridges and valleys, steep slopes and narrow valley floors. Some of these valleys are dry, while others are coursed by chalk streams with intermittent headwaters.
  • Sarsen stones (post-glacial sandstone blocks of Tertiary age) are known only at a few locations, for example Bradenham.
  • The Chilterns is part of a larger Chalk mass which functions as an aquifer. Unconfined areas of Chalk in the Chilterns represent key areas for re-charge (and pollution) of the aquifer. In addition to supplying local demand, the aquifer provides for London and the Thames.

River Thames valley and associated settlements including the important landforms of the Goring Gap and gravel river terraces.

Justification for selection:

  • The River Thames is culturally significant nationally and links the Chilterns to other NCAs within its catchment. Locally, it is an important recreational resource, a focus for settlement, an area of wetland interest and a major landscape feature.
  • The Goring Gap is a well-known landform created by the River Thames carving a passage through the Chalk ridge.
  • Quaternary deposits here are famous type localities for Thames river terraces, aiding our understanding of the evolution of the Thames course through geological time.
  • Being an important communication route and cultural attraction, historic features along the Thames are significant. There is a concentration of prehistoric monuments in the Thames Valley and internationally important prehistoric artefacts have been found in gravel terraces; for example, at Cannoncourt Farm Pit SSSI.
  • The Thames was also a focal point for some of the region’s finest houses and associated parkland and designed landscapes. Distinctive river frontages and ‘summer homes’ from the 19th century are a feature of Thames-side towns such as Marlow.

A diversity of semi-natural habitats and species special to the Chilterns.

Justification for selection:

  • A variety of soils which broaden the range of habitats beyond those typical of the Chalk. The extensive clay-with-flint deposits support acid heathland, grassland and woodland.
  • The Chiltern soilscape makes it possible for all native beechwood types to be present and also for small examples of rare chalk heath which comprise both acid-loving and calcareous plants. There are the dry beechwoods on acid soils; the oak-beech woods on heavy clays; and the beechwoods on thin, chalky rendzina soils.
  • Nationally important extremes of the beechwood series, the yew woods and box woods, are also present. Important wet habitats which contrast with the dry habitats on chalk; watercourses, springs and limited areas of fen and meadow are found in some valleys and along the foot of the scarp.
  • A few small areas of calcareous fen exist at Pitstone and Bledlow and, in the Thames Valley, there are SSSI wet meadows and fens between Henley and Cookham. Ponds form on impermeable clay-with-flint deposits and there are also man-made features including the Grand Union canal, mineral extraction pits and reservoirs such as Tring Reservoirs SSSI. The Thames and its valley represent the largest wetland feature and the Chess is the most significant of the chalk streams..
  • Downland, common land, meadow, parkland and woodland have created diversity of habitat at a local scale. Common land often exhibits features resulting from different land management practices, including wood pasture, heathland/grassland and secondary woodland; for example, Naphill Common SSSI and Frithsden Beeches SSSI.
  • The red kite and deer are numerous in this area and, as a consequence, have become strongly associated with the Chilterns.
  • There are several rare or scarce species associated with the Chilterns. Grassland plant species include Chiltern gentian, fringed gentian, early gentian, wild candytuft, monkey orchid, and military orchid. Woodland species include firecrest, a number of scarce deadwood beetles and flies and also fungi such as Devil’s or Satan’s bolete, old man of the woods, and Inocybe patonillardii. Box woodlands support a number of rare lichens and liverworts. Chalk stream species include the water vole and cowbane.

One of the most wooded lowland landscapes in the country, distinguishing the Chilterns from other more open chalk landscapes.

Justification for selection:

  • The Chilterns is one of the most wooded lowland landscapes in the country with over 23,000 ha of woodland covering 14 per cent of the NCA. The majority of woodland is broadleaved and much is native beechwood.
  • Over half the woodland resource is ancient. Extensive areas of woodlands have remained uncleared for centuries, particularly on steep slopes and over clay-with-flint deposits.
  • A variety of elements create this wooded landscape – farm woodlands, productive forestry, wooded commons, parklands (including designed woodlands, groves and tree avenues), orchards, hedgerow trees, field trees, hedgerows, gardens and roadside trees.
  • The Chilterns has the greatest extent of native beechwoods in the country. Chilterns Beechwoods SAC represents a major resource at over 12,000 ha. There are ‘hanging’ beechwoods on the upper slopes of the valley sides and on the scarp. Plantation beechwoods are renowned for their ‘cathedral like’ qualities.
  • Woodlands and hedgerows contribute to the seasonal variations in colour and are widespread enclosure elements creating a sense of intimacy and secrecy. There is a wealth of species in the typical Chiltern hedgerow including many typical of ancient woodland – hazel, field maple, holly, ash, elm, rose, dogwood, blackthorn, spindle, whitebeam and wild clematis.
  • The beechwoods have inspired artists and writers; for example, Paul Nash’s painting ‘Wood on the Downs’.
  • A strong association with the history of the country’s furniture industry, particularly chairs, including the ‘Windsor Chair’, which relied upon local woodland products.
  • The dense shade cast by some beechwood types supports a unique ground flora community including saprophytic orchids.
  • Secondary woodland, for example on commons, has greater biological interest than would normally be expected because of its origin from natural succession of chalk downland or old wood pasture with scattered pollards; for example, Naphill Common SSSI and Ashridge Commons and Woods SSSI.

An ancient landscape of commons, downland, woodland and field boundaries, fragments of preserved ancient land use patterns, historic monuments, settlements and routeways dating from prehistory to the more recent past.

Justification for selection:

  • The historic environment includes bronze-age barrows and field systems; iron-age forts and dykes; pre-Roman ‘co- axial’ patterns of parallel trackways and fields; Roman roads and villa sites; medieval churches, field patterns, strip lynchets and deer enclosures; ancient coppice woodlands; 18th century sawyer pits and parklands; and 20th century military trenches and ‘Metroland’™.
  • Prehistoric monuments are concentrated along two nationally significant historic communication routes passing through the Chilterns, the Ridgeway and the Thames.
  • Some ancient features are widespread and can be accessed and enjoyed by the public – ancient woodland, ancient boundaries, historic routeways including ‘holloways’™, historic field and settlement patterns, manorial wastes and commons. In the half of the NCA designated the Chilterns AONB, 45 per cent of the landscape is of pre-18th century origin and 42 per cent of fields are pre-18th century.
  • Nucleated settlements with historic cores are associated with watercourses and springs. Despite significant 20th- century development, some settlements appear little changed, for example the historic village of Turville. Medieval flint churches are numerous.
  • Common land accounts for 2,179 ha, or 2 per cent of the area, and ancient woodland 12,113 ha or 7 per cent of the NCA. Historic downland is almost exclusively found along the scarp and accounts for 2 per cent of the area of the Chilterns AONB. As well as preserving historic land use patterns, such areas of ancient downland, common land and woodland are also rich with historic features, including scheduled monuments.
  • Ancient woodlands contain features associated with the industry, including the local furniture industry that was at its peak in the 19th century. Secondary woodland also preserves features pre-dating woodland cover; for example, Boddington hill fort.
  • Many places have a long history of management. On commons, for example, there can be remnants of previous land uses within secondary woodland, including wood pasture, heathland glades and ponds. Chiltern commons have historically been managed for all their naturally occurring resources including as wood pasture, woodland, deer park, pannage and for mineral extraction.
  • Around 40 per cent of hedged field patterns in the Chilterns are thought to have pre-18th century origins, with distinctive Saxon parish boundaries surviving along the scarp. The Black Hedge near Great Hampden and the Hundreds boundaries are significant Anglo-Saxon features.
  • There are 4,696 ha of Registered Parks and Gardens over 40 sites, many being visually prominent in the landscape and accessible to the public. Parkland can contain both biodiversity interests, including woodland, veteran trees, grassland and heathland, and historic features surviving from pre-existing landscapes.

Fragmented species-rich chalk grassland on steep slopes, supporting rare plants and scrub communities including juniper, box and numerous orchids.

Justification for selection:

  • The resource is less extensive and more fragmented than other areas known for chalk grassland. This is the consequence of the unique combination of complicated topography, distribution of other habitats and pattern of land use over the centuries.
  • Chiltern grasslands are distinctive where they have a very short, highly diverse turf. A large number of rare and scarce vascular plant species have been recorded that are uncommon across other south England chalk grasslands. Several plant species are strongly associated with the Chilterns: Chiltern gentian, early gentian, fringed gentian, greater pignut. Many rare orchid species have been found and there are strong populations of some rare species such as the pasque flower at Barton Hills National Nature Reserve.
  • There are rich communities of invertebrates, liverworts and mosses including specialists of box and juniper scrub. Duke of Burgundy, small blue and chalkhill blue are butterflies of restricted distribution in the Chilterns.
  • Rare scrub communities include very important UK examples of lowland juniper scrub at Aston Rowant SSSI and Roughdown Common SSSI, and one of three sites in the country for native box scrub at Ellesborough and Kimble Warren SSSI.

Red brick and flint buildings are distinctive.

Justification for selection:

  • Settlement pattern and local vernacular building styles contribute greatly to the landscape character and a sense of history. Traditional building materials of brick and flint were historically used in all settings, from the farmstead to the village and town, and include churches, boundary walls and railway stations. Brick and flint continue to be used in some modern constructions.
  • Variations in the use of brick and flint create interest. Brick was often made locally, giving rise to variations of red colour, texture and quality. Bricks of varying colours and glazes were used to create ornamental details. Some buildings, including churches, may be constructed entirely from flint. The proportion of brick to flint is variable, as is the style.
  • Areas of 20th century development have introduced other styles and materials that can be dominant over the traditional character.

Localised and occasionally modified chalk streams.

Justification for selection:

  • Chalk streams and associated wetland habitats occur in an otherwise dry landscape and support a high diversity of plants and animals. Further importance is attached to them as globally scarce habitats confined mainly to England and north-west Europe. There are unique assemblages of plants associated with winterbourne sections.
  • In the half of the NCA designated the Chilterns AONB, important biodiversity is recognised by two SSSI and 30 Local Wildlife Sites which incorporate sections of chalk river.
  • Chalk streams only occur where groundwater reaches the surface in the chalk valleys and along the foot of the scarp. Chalk streams in the valleys tend to be minor landscape features except in the case of the Chess. Some watercourses are intermittent at their headwaters, for example the River Misbourne, or along entire stretches, such as Hamble Brook.
  • Numerous springs and watercourses arising at the foot of the scarp.
  • The River Lee passes through Luton and the River Wye through High Wycombe. Rivers are often near to major roads following the valley floors and consequently have a long history of modification and pollution to the extent that no Chiltern chalk stream can be considered to be ‘natural’.
  • Water meadows are found alongside the River Chess.
  • A localised feature, chalk streams are significant for their local biodiversity, history and community interest. There are six local community groups dedicated to the conservation of Chiltern chalk streams. Riverside urban green spaces and Barton Springs, for example, draw visitors.
  • Historic features include water cress beds along the Alderbourne and Chess, ornamental lakes as at Shardeloes, and mill remains.

An agricultural landscape of cereals and livestock intimately mixed with woodland and defined by ancient hedgerow boundaries.

Justification for selection:

  • A patchwork land use pattern of woodland and farmland. At the farm scale, there is often a mix of woodland and farmland, with woodlands having historically been a useful resource for the farm itself.
  • Much of the patchwork land use pattern is intricate because it has the ancient characteristics of being small-scale, irregular and defined by ancient boundaries and routeways. Today, the farmed landscape dominates land use, combined with very high woodland cover. Grade 3 land accounts for 66 per cent of the NCA and dictates a mix of arable and livestock farming.
  • Livestock numbers have been in decline but livestock farming continues and helps conserve remaining areas of downland and meadow. There are no rare/traditional breeds particularly associated with the Chilterns.
  • Orchards and watercress beds remain as relicts of once significant local industries.
  • Despite a dramatic decline in the last 50 years, the Chilterns still stands out as a national stronghold for arable weeds including pheasant’s eye, ground pine, broad-leaved cudweed and rough mallow. Areas of less intensive agricultural land, for example field margins, host these species.
  • A 2002 survey in the Chilterns AONB found that there are nationally important populations of farmland birds including corn bunting and linnet. Above average populations of skylark and yellowhammer were also found. However, species such as stone curlew are no longer present.
  • Species-rich grassland is present in the farmed landscape on limited areas of downland and meadow. In the part of the NCA designated the Chilterns AONB, a survey in 2006 and 2007 identified that there were many veterans amongst the hedgerow trees and 38 per cent of hedgerows surveyed were in good condition.

Features linked to recreation are widespread, including an extensive rights of way network, open access land, horse paddocks and golf courses.

Justification for selection:

  • Areas of downland and the numerous scattered commons are designated as open access land. The extensive woodland resource also contributes to the area of open access. Open country includes key locations along the scarp, providing access to magnificent views, species-rich grassland and scheduled ancient monuments.
  • Commons are key green spaces within the villages, towns and larger urban areas and are scattered across the NCA. They are particularly important in more developed areas such as the Thames Valley, for example Cookham commons, and on the edge of London at places such as Chorleywood and Harpenden.
  • Popular visitor sites include Ashridge, Coombe Hill, College Lake, Tring Reservoirs, Wendover Woods, Dunstable Downs, Pegsdon Hills and Barton Hills. Recreation infrastructure including car parks, visitor centres and signage are associated with some popular green spaces, such as Dunstable Downs. Areas of tranquillity are significant in a
    landscape that is near to London, cut through by major transport routes and subject to development pressures. The scarp plateau, especially in the south, is the most tranquil area.
  • Accessibility by road has not been upgraded from single track lanes in some places and such areas feel ‘secret’ and tranquil; for example, Bix Bottom near Henley and Radnage Valley near High Wycombe. It is also possible to ‘escape’ where there are significant enclosure features such as narrow valleys, woodland, holloways and hedgerows.
  • The rights of way network is considered good. There are promoted routes incorporating all the key landscape attributes of the Chilterns, including ‘Access for All’ routes in the Chilterns AONB. Promoted routes include two National Trails, the Thames Path and the Ridgeway – towpaths along the Grand Union Canal and National Cycle Network routes.
  • Water-based recreation is possible along the Thames and Grand Union Canal, including fishing, boating, canoeing and birdwatching. Limited access is provided to the chalk streams, for example, Barton Springs is on open access land.
  • With over 10 million people living within an hour’s drive or train journey, many people can benefit from the tranquillity and recreation opportunities of this area.
  • Areas of recreational use comprise over 2 per cent of the Chilterns AONB and consist of golf courses, playing fields, theme parks and zoos. The largest of these categories is golf courses. Some Registered Parks and Gardens are accessible to the public at cost, including National Trust properties such as Hughenden Manor and Greys Court.
  • In the half of the NCA designated the Chilterns AONB, a survey suggests that 5 per cent of the AONB is used for equestrian purposes and there are promoted horse riding routes. Subdivision of fields into paddocks is particularly evident near settlements.

A settled landscape with 20th century development associated with major transport routes, but with small-scale, dispersed settlement and single track country lanes found off main routes.

Justification for selection:

  • Settlement is dispersed and there are major transport routes passing through the area. The built environment is therefore very much part of the Chiltern landscape, although the level of development varies across the NCA.
  • Good lines of communication with nearby London have been critical to the development of the area and also essential to a wider transport network which links London to the Midlands and the North. Beginning with the turnpike trust improvements to the main routes during the 18th and 19th centuries, links have been strengthened and include London’s transport network of the Grand Union Canal, railway lines and several motorways.
  • Some settlements have been a particular focus for 20th century development due to their proximity to London and major transport routes. ‘Metroland’, which incorporates Amersham for example, was specifically developed and promoted in the early 20th century as a residential area for London commuters on the Metropolitan line. One of the first ‘new towns’ in the NCA, Hemel Hempstead, was designated in 1947.
  • Very limited 20th century expansion is found where the road network is small-scale. The plateau and valleys south of the M40 is a large area characterised by single track lanes and scattered farmsteads, hamlets and small villages.
  • In 2003, approximately 41 per cent of the NCA was included in the London Metropolitan Green Belt.

Frequent grand country houses and designed landscapes occupy prominent positions.

Justification for selection:

  • The proximity to London and Windsor attracted the landed elite in the 18th and 19th centuries. Grand country houses and parks reached their peak at 600 in 1820. Today 3 per cent of the NCA is included in the Register of Historic Parks and Gardens.
  • Designed landscapes of the 18th century, for example Tring Park and Ashridge, are best known and include works by Bridgeman, Repton and Brown. Some are associated with high profile figures including Chequers, the Prime Minister’s rural home, and Hughenden, a home of Victorian Prime Minister Disraeli.
  • Public access is possible to many country houses and landscapes, including properties owned by the National Trust and others.

Landscape opportunities

 

  • Protect the character and integrity of the rural landscape, by conserving the combination and balance of key assets; boundary features, semi-natural habitats, tranquillity and historic buildings.
  • Identify and conserve views to and from key and popular viewpoints and landmarks by careful design and vegetation management, minimising the impact and effects of development, woodland planting and scrub encroachment.
  • Conserve the patchwork land use pattern, valued farmland species and productivity of the landscape by securing sustainable forestry and mixed agricultural activity. This includes conservation of small farm woodlands, historic hedgerows, farmland birds, woodland birds and arable weeds.
  • Plan and manage private and public spaces for recreation, such as golf courses and hobby farms, so that their design and their features positively contribute to landscape character. Seek the conservation, restoration and creation of natural and cultural features in these landscapes.
  • Secure sustainable development which also reflects traditional local building styles and materials both within and outside the AONBs of the Chilterns and North Wessex Downs. Where landscape character and features are degraded by development, identify opportunities to re- develop areas and infrastructure, for example; re-modelling canalised sections of river and restoring key views.
  • Conserve the range and mosaic of habitats found in the landscape by protecting traditionally managed or relict features such as chalk grassland, coppice woodland, orchards, laid hedgerows, veteran and ancient trees and commons.
  • Support marginal and localised land management practices and develop ‘products’ attractive to modern consumers, including leisure products, local brands and wood fuel.
  • Seek to reduce threats to natural and historic features by conserving or restoring their setting, addressing the problem of fragmentation particularly associated with chalk grassland and common land. Work at a landscape scale which reflects the ecosystem approach, ecological network approach and historic landscape character areas.
  • Conserve, enhance and create new public access infrastructure, access links and accessible natural and cultural features, particularly near to settlements, in order to enhance the transitional areas between town and countryside and conserve tranquillity. Undertake appropriate visitor management to ensure sustainable visitor pressure at all sites but particularly focus upon ‘honey pot’ sites and those sites near to new development. Identify and promote alternative green spaces and entry points to reduce visitor pressure.
  • Conserve the extensive woodland cover and diversity of wooded features, particularly the ancient woodlands, native beech woodlands and wooded features in designed landscapes, in order to conserve the sense of place, biodiversity and historic landscape. Restore plantations on ancient woodland sites. Plan to improve the understanding of the extent and management requirements of the rare yew and box woods. Plan to build the resilience of woodlands to climate change impacts, particularly the valued beech woodlands which are vulnerable. Consider new species compositions and secure woodland across a variety of aspects.
  • Engage landowners and managers of parklands in the management of trees and woodlands, particularly those outside grant schemes and those that are ‘At Risk’. Conserve the best examples and variety of Chiltern parklands, maintaining their legibility and contents and ensuring management brings about positive outcomes for access and interpretation, biodiversity and the historic record. Manage veteran and ancient trees, woodlands and grasslands in parklands to strengthen biodiversity value.
  • Conserve ancient routeways and existing hedgerow boundaries across the landscape to conserve boundary patterns and biodiversity. Create new hedgerow boundaries to fields and routeways to restore historic field patterns and benefit biodiversity, Carry out targeted surveys and possible Local Wildlife Site designation to conserve species-rich hedgerows and identify hedgerow trees of significant landscape and biodiversity value.
  • Protect chalk streams and wetlands through securing sustainable levels of water abstraction and through pollution prevention measures in both their rural and urban settings. Harness catchment-scale approaches, recognising the entire length of chalk streams and groundwater resources. Pursue Local Wildlife Site designation to secure protection as appropriate.
  • Manage the flood plain of chalk streams, including historic features such as watercress beds and channels, in order to conserve and create wetland habitat, filter runoff; and store water. In the urban environment, seek to restore degraded channels and extend the area of green space surrounding rivers for biodiversity, flood alleviation and public access benefits.
  • Manage recent change in the landscape by establishing a dialogue with growing stakeholder groups, particularly hobby farmers, horse-owners and non-farmers owning significant areas of land and valued features. Develop best practice management guidance to disseminate to these growing audiences.
  • Build on existing community interest and activity around chalk streams and common land to secure further improvements.
  • Create urban fringe areas that deliver a variety of functions and contribute positively to sense of place. Create strong visions which help to manage land that is ‘awaiting development’.