130 - Hampshire Downs : Description

Physical and functional links to other National Character Areas

The Hampshire Downs are the central block of a broad belt of chalk downland that runs through southern England from west Dorset to East Sussex and Kent. North-west and west of Hampshire the landscape morphs imperceptibly into the Berkshire and Marlborough Downs National Character Area (NCA) and the Salisbury Plain and West Wiltshire Downs NCA. To the south-east the landscape rises to form the South Downs. Steep scarp slopes mark the boundary with the Thames Basin Heaths NCA to the north and, in the east, the East Hampshire Hangers mark the boundary with the Wealden Greensand. To the south the transition is more gradual, descending to the South Hampshire Lowlands and the South Hampshire Coast Plain NCAs.

This major aquifer is the source of rivers flowing into three systems: short sections of the Loddon, Lyde, Wey and Whitewater flow north and east from their source on the Chalk into the Thames; the Rother, from the base of the Hangers, flows east to join the Arun; while the Test and Itchen, in long narrow valleys, flow south through the Chalk to Southampton Water at the centre of the Hampshire Basin. The latter are the key fluvial features of the NCA and their waters provide not only a quality domestic source for the Southampton and Portsmouth conurbations, but also fresh, clean water for the aquatic habitats of the river systems and their flood plains and for the natural harbours, estuaries and marshes of the North Solent shore.

The elevation and steepness of the northern scarp provide long-distance views over the Thames Valley, and a clearly demarked ‘north face’ of the Downs if looking, or travelling, south. Similarly, the wooded scarp of the Hangers dominates the skyline viewed from the A3(M) and Petersfield in the east, clearly marking the edge of the Chalk and the start of the Upper Greensand of the Weald.

Major radial transport arteries cut through the Downs connecting London with Hampshire and the South West: the M3, A31, A303 and the main railway lines from London Waterloo to Salisbury, Southampton, Bournemouth and Poole, and Weymouth. The A34 cuts north-south through the centre of the NCA connecting Southampton docks with the Midlands. Traffic on these routes has a significant impact on the landscape.

The Hampshire Downs today

The Downs are an elevated block of Middle and Upper Cretaceous Chalk that rises to 297 m at Walbury Hill near Inkpen in the north-west, from where it descends gradually to approximately 100 m to 150 m in the south. The countryside is large-scale, open and rolling, with broad, gently domed, undulating plateaux and distinct hill tops, ridges and scarps, which are dissected by both steep and shallow valleys. Soils are mainly free-draining, thin chalky loams, with heavier, younger clay-with-flint soils on the caps and some of the valley sides. These coincide with much of the scattered woodland in an otherwise uniform arable landscape of large fields, shelterbelts (many of them acting as cover for game birds) and low, thin hedgerows. A northerly scarp (much of it calcareous grassland), from Inkpen to Cottington’s Hill near Kingsclere, overlooks the Thames Basin; and an eastern scarp, from Selborne to Langrish, which is heavily wooded with beech and known as the ‘East Hampshire Hangers’, twists sinuously north-south overlooking the Weald. The outstanding scenic quality of the landscape, in parts of the area, is recognised in the designations of the North Wessex Downs Area of Outstanding Natural Beauty and the South Downs National Park.

Cutting through this high, chalk landscape are the valleys of the rivers Itchen and Test. These are relatively narrow, with steep sides in places, and flat, lush valley bottoms of thick peaty and gravel deposits, through which flow fast, clear streams with a rich diversity of aquatic plants, insects and varieties of fish, including trout and salmon. At the head of the valleys and in small side valleys, flowing water can be seasonally intermittent, hence their name – ‘winterbournes’. The main rivers, with fast-moving, well-oxygenated water, are largely fed by the chalk aquifer and much of the characteristic wildlife associated with these aquatic habitats is dependent on the quality and content of this water.

Although these watercourses appear ‘natural’, many have been engineered – for example, to power mills or for agricultural (watermeadows) or flood management reasons – often increasing the biodiversity until the mid 20th century when some engineering of watercourses resulted in some meadows and side streams drying out and losing their value for biodiversity.

In contrast to most of Hampshire, early clearance of the Downs has left relatively few areas of ancient woodland; where they remain most are associated with claywith- flint soils of varying acidity, or with thin chalk soils on steeper slopes. The most extensive and important are the ancient sessile oaks in Harewood Forest near Andover; Crab Wood near Winchester with a rich diversity of woodland plants; Thorneycombe Wood near Vernham Dean with stands of wych elm and ash and field maple; and, the East Hampshire Hangers and Ashford, Noar and Selborne.

Across most of the downland, land use is dominated by intensive arable farming of cereals and fodder crops, some rotation pasture, and pig and cattle farming. This land management works within a framework of large historic fields. Some with sinuous boundaries and species-rich hedgerows with trees dating from 15th century and later enclosure, often in tandem with the establishment of farmsteads over that period. Regular enclosed landscapes, especially on the thinner soils, date from the late 18th century and have the largest fields and farmsteads, the latter often with workers’ houses; here hedgerows can often be low and thin. Hedgerow quality has, however, improved recently as a result of agri-environment agreements. The thin chalk soils throughout the area enable high levels of spring cropping that are above the national average and support populations of rare arable flora. In contrast, the valley bottoms have a more intimate landscape of small fields, which have in many places been drained for arable crops, or for permanent grassland for cattle and sheep – the latter including widespread use of the locally distinctive ‘Hampshire Down’ breed.

The main semi-natural habitats are remnant chalk grassland, along the northern scarp and scattered throughout on commons; ancient woodlands (see above); the river valleys with chalk streams and aquatic valley habitats; and field margins that are the most important area in England for plants of arable cultivation and disturbed soils.

Of these the most important international designation is the River Itchen Special Area of Conservation (SAC), which covers the entire river and some of its flanking meadows. This is designated because the river supports several species of watercrowfoot and the presence of southern damselfly, bullhead fish, white-clawed crayfish, brook lamprey, salmon and otter. The quality of the Itchen Valley landscape, its habitat and recreation interest, led to its inclusion in the South Downs National Park. The valleys and watercourses of both the Itchen and the Test, and other rivers such as the Whitewater, support several other rare and important wetland species and habitats, such as those found at Greywell Fen.

In the south-west, the woodland around Mottisfont (National Trust), on the western flank of the River Test, is also an SAC principally because of the maternity site and foraging area for barbastelle bats, although nine other bat species also occur. This area is also important for fritillary butterflies.

In the south-east, the East Hampshire Hangers SAC is designated for its beechassociated vascular plants, mainly hellebores and rare bryophytes.

Three major settlements dominate the Downs. Winchester, with its cathedral, college and historic town centre, developed on an ancient meeting of trackways (‘dongas’) at a strategic crossing point of the Itchen. This was a major Roman settlement, the pre-Norman capital of England, and is now the home of county administration and an increasingly popular international visitor attraction.

Andover (at the head of the Test catchment) and Basingstoke (at the head of the Loddon) are two market towns that were expanded to accommodate the London overspill population after the Second World War. Largely 20th century, urban features demonstrating planned communities, they continue to experience rapid economic and housing growth. The river valleys provide the focus for smaller, nucleated settlements and market towns such as Alresford, Stockbridge, Whitchurch and Overton, and the communications that connect them.

Major transport arteries cut through the Downs connecting London with Hampshire and the South West: the M3, A31, A303 and the main railway lines from London Waterloo to Salisbury, Southampton, Bournemouth and Poole, and Weymouth. The A34 cuts north-south through the centre of the NCA connecting Southampton docks with the Midlands. Traffic has a significant impact on the landscape, but, away from these roads and the main towns, levels of tranquillity and remoteness remain relatively high, particularly in the area north-west of Andover, towards the South Downs, and in the river valleys. These features are all valued by walkers, cyclists and horse riders who are well served by a dense rights-of-way network. Offroad cycling is very popular, attracting large numbers using the specific routes promoted by the county council. There are several, well-used, long-distance routes, such as the Wayfarers Walk along the Chalk scarp, and the Clarendon Way connecting Winchester and Salisbury.

The rivers Test and Itchen are both internationally renowned as the birthplace of fly fishing. This attracts anglers from all over the world, supports an important and prestigious industry, and has been the literary inspiration for influential fishing writers such as Frederic Halford and Harry Plunket Greene.

The Hampshire Downs have inspired many artists and authors, notably the naturalist Gilbert White on Selborne Common, Jane Austen at Chawton, and Richard Adams at Watership Down. The chalk rivers have been remarked on by many authors, notably Isaak Walton, writing in 1676. William Cobbett, writing in 1825, vividly describes the landscape and farming practices of the Downs as he rode from Winchester to Whitchurch.

The landscape through time

The Upper Cretaceous Chalk, forming the main bedrock geology of this NCA, was deposited in a warm, shallow, tropical sea between 75 and 90 million years ago. It has retained its horizontal bedding across most of the area, but in places shows evidence of folding and tilting caused by earth movements related to the Alpine orogeny that elevated this landscape. Occasionally outliers of the older Middle Chalk strata, distinguished by their lack of flint nodules, have been exposed. Most exposures of the Chalk are confined to the coast, but in this NCA there are a few places – for example, Ladle Hill Site of Special Scientific Interest (SSSI) near Burghclere – where it can be studied inland.

The distinctive, incised, straight-sided valley systems of the chalk streams are a product of post-glacial erosion of the chalk bedrock that remained frozen and therefore not porous. Rivers, swollen with meltwater and eroded material, cut the deep valleys with wide bottoms in which now flow much smaller watercourses. This phenomenon also explains the numerous dry valleys at the upper end of the catchments, now unable to hold water because of the porosity of the bedrock, except when swollen after heavy – usually winter – rainfall. As rivers slowed, this allowed the deposition of sediment and plant material which, because of the high water table, allowed deep peat beds to accumulate.

Clearance of the primeval forest cover and evidence of human occupation date back to the Neolithic period when, about 4,000-6,000 years ago, agricultural practices enabled settled communities to develop, helped by the local abundance of flint for tool making. The most notable evidence, in the form of long barrows, occurs in the remnant chalk grasslands of the northerly scarp. Woodland clearance continued during the Bronze Age and Iron Age, agriculture intensified, field systems and settlement hierarchies were established, and the hill forts such as Danebury and Burghclere beacons were built. Also at this time, many of the ancient trackways following higher ground across the Downs, now familiar as footpaths such as the Wayfarers Walk, were established. The Romans added their own roads between their major camps and settlements, many of them now followed by modern roads such as the A33 north of Winchester. In addition to opening up the landscape, woodland clearance and early agriculture also led to widespread erosion of the former deep, noncalcareous, forest soils and the formation of the thin soils upon which the chalk grasslands developed.

During the Anglo-Saxon period, farming developed further and much of the framework of the modern-day land divisions was established, along with the beginning of settlements focused in the upper valleys. A notable surviving feature of this early pastoral farming is the ‘ladder’ field system that links valley-bottom meadows with woodland and cleared downs on higher ground, many of the boundaries surviving as banks, ditches and parish boundaries.

King Alfred is associated with the establishment of Winchester as the capital of Wessex, which developed in the late Saxon period as a centre for trades and commerce with a cathedral, royal mint and garrison. Modern estimates suggest that up to 50 per cent of the woodland had been cleared by this time, although the influence of Forest Laws to protect land for hunting began to have an effect. Medieval influences can be clearly seen in the lush bottoms of the Itchen and Test valleys where the parish boundaries are still reflected in field boundaries and tracks, and the settlement pattern is highly nucleated and very low density.

The 15th and 16th centuries saw a rise in the importance of arable and sheep farming on the Downs, often driven by large-scale renter farmers, and this period represents the maximum extension of the chalk grassland. Woodland continued to be cleared, but many of the remaining woodlands were intensively managed to support the thriving sheep economy, producing large quantities of hurdles from coppiced hazel, with oak and ash standards. During the same period the flood plains began to be intensively managed as watermeadows, a system of critical importance to sheep and dairy farming, providing an early spring flush of growth and a rich source of hay for winter. Animals were also used to fertilise arable land by turning them out overnight.

Arable farming continued to develop over the 17th and 18th centuries, driving the gradual and planned enclosure of downland which had reverted to grass since the 14th century. The decline of the sheep economy during the 19th century and the need to produce more home-grown cereals led to the ploughing of increasing areas of chalk grassland and the gradual dereliction of the old watermeadows. Nevertheless, the distinctive pattern of ridges and furrows is still widespread in the valleys – a precious historic landscape that supports rich flora and invertebrate life.

The area of chalk grassland has historically fluctuated; however, the last fifty years have seen an unprecedented level of chalk grassland being ploughed, or reverting to scrub. Today unimproved (species-rich) chalk grassland is confined to the steepest slopes: marginal land out of the reach of machinery, or land managed primarily for conservation.

Game fishing, which began in chalk rivers in the 19th century, has become a highvalue land use and the rivers Itchen and Test are largely managed to this end. This has resulted, in the past, in some distortion of the natural fish stocks, weed cutting with implications for silt deposition and channel erosion, grazed banks of the watercourses being fenced and regular mowing of bankside paths. More sympathetic management is being slowly introduced that can benefit the natural ecosystems as well as fly fishing.

Continuing growth in population, housing and economic development in South Hampshire, Basingstoke and Andover affects the Downs in several ways, but also benefits from their proximity as a recreational outlet, with benefits for health and wellbeing. Direct effects are the increasing visual impact of towns and cities visible from the Downs, increased traffic, noise and lighting. More indirect effects are the pressures on water supply and quality through abstraction, pollution and sewage discharge.