National Character Area 118

Bristol, Avon Valleys and Ridges - 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

Contrasting landscape of low lying shallow vales, limestone scarps and downland ridges strongly influenced by the complex and diverse geology that is reflected in the many geological SSSI and the diversity of vernacular building stones in use.

Justification for selection:

  • Complex and diverse geology ranging from early Ordovician to Middle Jurassic in age, and comprised of limestones, mudstones, siltstones sandstones, conglomerates and coal, influenced by several phases of folding and faulting. The area played an import role in the history of the development of geology as a science as William Smith (the ‘father of English geology’) based some of his founding geological principles upon strata and features exposed within the area.
  • 25 geological SSSI plus an additional 2 of mixed interest.
  • Important fossil bearing strata are visible in some geological exposures for example: fossil fishes at Woodhill Bay; corals, brachiopods and crinoids in the Carboniferous Limestone; Coal Measure plants and insects at Writhlington; high dominance low diversity bivalve assemblages in Late Triassic sediments, underlying the south and the east of Bristol; Lower Jurassic sediments containing rich fauna including ammonites, nautiloids, bivalves, brachiopods, belemnites and marine reptiles such as ichthyosaurs.
  • The mineralogical interests of the NCA lie mainly in small areas of sulphides mineralisation (copper, zinc and arsenic), and the extensive deposits of celestine (stronium sulphate) that occurs in the Mercia Mudstone Group.
  • Local stone such as local ashlar which includes pale yellow Jurassic oolitic limestones, grey Carboniferous
    and Lias limestones used as building materials, or, in some locations in the north, red or brown sandstone.

Long historic timeline visible in the landscape, historical significance of access to the Severn Estuary through the Avon and its ports.

Justification for selection:

  • 21 Registered Parks and Gardens covering 1,723 ha, 117 Scheduled Monuments and 4,822 listed buildings.
  • Evidence of Neolithic activity in the long barrows and stone circle at Stanton Drew.
  • Iron-age hill forts, for example Cadbury Hill, and evidence of settlement of lower-lying clay vales.
  • Importance of the port at Sea Mills during the Roman period and evidence of villas either side of the Avon Valley and on the fertile soils north of the Mendip Hills.
  • Significant ‘Dark Age’ settlements on the eastern edge.
  • The 6th century Saxon Wansdyke cutting across the ridges south of Bristol and important centres at Pucklechurch, Chew and elsewhere by the later Saxon period.
  • Bristol historic port and buildings associated with trade with the colonies since the Tudor era, the wealth that it generated is evident in the parks and mansions that surround the city such as Dyrham Park, Tyntesfield, Dodington House, Blaise Castle and Ashton Court.

Distinct limestone ridges characterised by important extensive ancient woodland and the internationally important and downs.

Justification for selection:

  • The higher ground and steep scarps of the limestone ridge extend from the Yeo Valley towards Thornbury. The frequently heavily wooded scarp falling steeply away westwards to the levels of the Severn Vale.
  • The limestone ridge cut by the spectacular Avon Gorge on the edge of Bristol, with its cliffs and quarry exposures of Carboniferous Limestone, its screes, species-rich grassland and ancient woodland habitats that support rare and unique species such as the Bristol onion and Bristol rock-cress and grow nowhere else in the UK, and rare whitebeams (Sorbus species) including S. bristoliensis and S. wilmottiana which are unique to the Avon Gorge.
  • The Avon Gorge is internationally recognised as a European Special Area of Conservation (SAC) under the Habitats Directive 1992 for its ‘mixed woodland on alkaline soils associated with rocky slopes (Tilio- Acerion ravine forests) for which this is considered to be one of the best areas in the United Kingdom’.
  • Peregrine falcon and raven nest within the gorge.
  • The limestone to the south forms the distinctive landscape of the Failand Hills with their extensive sometimes panoramic views, which together with the gorge woodlands form the greatest expanse of ancient woodland in the NCA.
  • The Clifton Suspension Bridge, a Grade I-listed building and strong cultural symbol of the City of Bristol.

Contrast between the more densely settled and varied landscape of low lying, shallow vales and the open unsettled limestone scarps and high open downland ridges.

Justification for selection:

  • Tremendously varied farmed landscape, ranging from large fields with intensive arable cropping to small pastures with dense hedges.
  • On the limestone areas, villages cluster around the scarp foot springs and locally in the lower parts of the combes, with farmsteads occurring on the ridge tops where they are mainly contemporary with enclosure in the 18th and 19th centuries, and also on sheltered sites lower down.
  • Gentle open landscape of the clay vales in the east, with few hedgerow trees, giving way to an intricate field pattern mixed with woodland on the surrounding higher land. Villages are more widespread in the clay vales as are scattered farmsteads and hamlets linked by a complex network of lanes and track ways. Many of the villages are tightly clustered around a church but settlements like Timsbury are more straggling.
  • In the former mining areas, the settlements are interspersed with rows of cottages and isolated houses strung out along the minor roads. Small towns like Paulton and Norton-Radstock, have been formed by the spread of the mining industry in contrast to the ancient settlements like Pucklechurch and Thornbury clustered around a church on higher ground.
  • A rolling landscape of rougher hill-top pastures and deep river valleys containing lusher pastures. Many stone villages and hamlets, and farmsteads linked by narrow hedged lanes to the south-east, merging with the eastern part of the Mendip Hills.
  • Pattern of medieval hedge-bound irregular fields, in the valleys and on steeper slopes (predominantly in the south-east).
  • Traditional stone walls in the shallow broad valleys, farmed Coal Measures and on areas of downland.

Strong contrast between large urban conurbation and rural and historical parkland landscapes.

Justification for selection:

  • Striking Avon Gorge with urban conurbation of Bristol spreading down to the river at Clifton beneath the suspension bridge.
  • Development along the M4 and M5 corridors, together with the regional shopping centre and major office development north of Bristol, dominate the open, undulating countryside around them which has little tree cover.
  • Clifton Downs and the Failand Ridge with extensive views over the conurbation of Bristol and across the estuary to Wales, or back towards the Chew Valley.
  • On the edge of Bristol, Ashton Court is the grandest of the parks that has used the limestone landforms to create landscaped deer parks and provides a wide range of active recreation pursuits such as kite flying and mountain biking for the populations of Bristol and North Somerset. It is also host to an annual international balloon festival.
  • To the south and east, housing extends to Dundry Hill and is broken by fragments of farmland. While in the north and north-east, development is dispersed across a wide area and the motorways are prominent. Modern residential development, extending as far as Yate, is broken by open farmland.

Semi-natural habitats including neutral and calcareous grassland, wet grassland, open water, species-rich hedgerows, traditional orchards, veteran parkland trees and drystone walls of biodiversity significance.

Justification for selection:

  • There are 51 SSSI wholly or partly within the NCA covering 2,083 ha, 2 per cent of the area. Twenty-five of these are geological, the remainder mostly cover grassland (calcareous or neutral) and/or ancient woodland features.
  • Lower Woods SSSI near Wickwar is the most extensive ancient woodland in the area, creating a mosaic of ancient woodland and species-rich grassland, with the SSSI extending to 280 ha. Pedunculate oak and ash dominates, with hazel and field maple as an understory. Ground flora species include dog’s mercury, bluebell, wood anemone and wood sorrel.
  • Small-leaved lime is a tree which is only ever found on ancient woodland sites and it is characteristic of many of the woods on the limestone ridges to the south and south-east of Bristol.
  • Damper willow and alder woodland is found fringing Blagdon and Chew Valley lakes. On the more acidic soils, such as at Bickley Wood, sessile oak and birch predominate.
  • Diverse landscape of woodland edge, hedgerows, grazed pasture and watercourses with many caves and old buildings providing hibernation sites, making the area highly important for greater and lesser horseshoe bats, particularly around Ashton Court, Tyntesfield, the Failand Ridge, Barrow Gurney, Dundry Hill and Lower Woods.
  • Particularly fine examples of neutral grassland (MG5, lowland meadow) around Chew Valley and Blagdon lakes, Ashton Court, Butcombe, Nempnett Thrubwell and Walton Common.
  • Wet grassland and wet woodland associated with the river flood plains and the biodiversity value of the rivers themselves.
  • Species-rich hedgerows and drystone walls act as corridors for biodiversity across the landscape, connecting semi-natural habitats, grassland being of particular relevance to the walls, which also support lichens, bryophytes, vascular plants and invertebrates, while hedgerows can form an important part of the woodland and grassland network including linking traditional orchard and wood pasture and parkland. Drystone walls can also be of landscape, geological, cultural, biodiversity and historical interest. Orchards are concentrated on the south facing slopes to the north of the Chew Valley.
  • Chew Valley Lake SPA, internationally important for shoveler ducks and nationally important numbers of gadwall, tufted duck and teal. Blagdon Lake, also important for overwintering wildfowl, is an SSSI, supporting a diverse invertebrate fauna, particularly snails and water beetles. Aquatic and emergent plants and the surrounding species-rich lowland meadow add to the nature conservation value of the area.

Good provision of rights of way and access land.

Justification for selection:

  • There are 2,161 km of public rights of way, 2 km of the Cotswold Way National Trail and parts of the Bristol to Brecon, Bristol and Bath Railway, Bristol-City-Triangular Walk, the Celtic Way, Severn Way, Monarch’s Way, Frome Valley Walkway and Samaritans Way South-West (Bristol to Lynton) long distance paths within the NCA.
  • Good provision of cycle paths; Bristol also recognised as Britain’s first cycling city.

Landscape opportunities

  • Maintain, restore and consolidate areas of semi-natural grasslands that have an important role in accentuating underlying geology and in maintaining a sense of locality, to create a functional and resilient grassland network. Protect and manage species-rich lowland calcareous and neutral grasslands (priority habitat lowland meadow) and wet meadows and pastures for the species they support. Road verges also play an important part in linking grasslands.
  • Retention of semi-natural grasslands is also important in maintaining ridge and furrow, which is a distinctive landscape feature, and other buried archaeology and historic earthworks.
  • Continue to encourage the conservation and active management of existing woodland including ancient woodland, mixed woodland blocks, and shelter belts and promote new planting in accordance with the objectives of the Bristol and Avon Community Forest for their contribution to the landscape, recreation and biodiversity. Bolster the woodland network by managing hedgerows appropriately to link woodland, with other wooded habitats such as traditional orchards and wood pasture and parkland.
  • Manage traditional orchards to ensure a continuity of deadwood and rot holes and increase the variability of age structure of orchard trees. Improve the condition of the underlying grassland to enhance the lowland meadow resource. Restore or maintain traditional orchard buildings such as cider houses, which contribute to the history and cultural associations of orchards. Promote educational opportunities and visitor interpretation associated with the cultural features of traditional orchards.
  • Manage and restore field boundaries including hedgerows, hedgerow trees and drystone walls, and drainage ditches in keeping with local styles and management traditions.
  • Plan for increasing urban fringe pressures on agricultural land by active management and enhancement of green spaces in the urban fringe. This includes farms and agricultural land that all contribute to a network of green spaces and green corridors and to the conservation of landscape and biodiversity in the urban fringe.
  • Enhance farmland for farmland birds and rare arable plants.
  • Insensitive development and alterations in villages has affected rural character. Residential development pressure, along the M5 corridor and around the Bristol conurbation, has also had an impact. Promote village design statements and neighbourhood plans to help retain rural character.
  • Actively manage and improve the quality of sustainable recreational opportunities and associated infrastructure to enable more opportunities for people to be inspired by the downs, country parks and open spaces.
  • Manage the continued quarrying of the limestone ridges south of Bristol and plan for continuing pressure for expansion.
  • Conserve and provide interpretation for the area’s rich and complex industrial history, particularly features associated with the coal industry, rural mills colonial trading and industrialisation.
  • Retain the distinctive parkland character of the NCA, with the retention, appropriate management and replacement of parkland trees within a pastoral setting, and maintain distinctive tree lines and groups.
  • Conserve ancient and veteran trees in the parkland landscape for the benefit of fauna and flora that depend upon them and their heritage value. Plan for the provision of veteran trees of the future.
  • Enhance and protect the river landscape, particularly the River Avon which has the potential to unite the landscape through which it runs. Develop enhancements through landscape-scale approaches to conservation.
  • Conserve and protect geological sites and provide physical access and interpretation to improve the understanding of the significance of this area in the development of the history of geology and provide opportunities for sustainable recreation and tourism.