87 - East Anglian Chalk : Description

Physical and functional links to other National Character Areas

The East Anglian Chalk of Bedfordshire, Cambridgeshire, Hertfordshire, Suffolk and north-west Essex forms a narrow continuation of the chalk ridge that runs southwest-north-east across southern England, continuing in the Chilterns National Character Area (NCA) and along the eastern edge of The Wash. The northern boundary is clearly defined by the base of the north-west-facing chalk scarp slope, around the southern limit of Cambridge and along the fenland edge. From the higher ground to the south-east there are wide panoramas across the Bedfordshire Claylands NCA and the adjoining Fens NCA. To the north-east, sandy soil is blown over the Chalk, exerting a shared ‘breck’ character with the neighbouring Brecks NCA, visible in characteristic knarled Scots pine hedgerows. To the south and east it is bounded by the overlying chalky boulder clay of the South Suffolk and North Essex Clayland NCA, which includes Saffron Walden. The Wadlow Wind Farm, north of Balsham in Cambridgeshire, is a prominent feature along the boundary between the two NCAs.

The chalkland landscape is united with the rest of the East Anglian NCAs as a major food producer, with arable farming being the predominant land use. The smooth, rolling chalkland hills are dissected by the two gentle valleys of the rivers Granta and Rhee, which converge flowing westward into the River Cam just south of Cambridge. The Rhee begins at Ashwell Springs in Hertfordshire, running north then east 19 km through the farmland of southern Cambridgeshire. The longer tributary, the Granta, starts in Essex and flows north into the East Anglian Chalk NCA near Saffron Walden. The underlying chalk aquifer provides functional links between these areas and the population of East Anglia, whose water the aquifer supplies.

The East Anglian Chalk NCA is traversed by a major prehistoric routeway, the Icknield Way, which links the Peddars Way and The Ridgeway National Trails. Important strategic railways and road transport links still exist, including the M11, A14, A505 and A10 (Ermine Street).

The East Anglian Chalk today

The East Anglian Chalk of Bedfordshire, Cambridgeshire, Hertfordshire, Suffolk and north-west Essex forms a narrow continuation of the chalk ridge that runs south-west-north-east across southern England, continuing in the Chilterns and along the eastern edge of The Wash.

This is a visually continuous, open landscape, with occasional long views over the lower land to the north and west. The valleys of the rivers Granta, Rhee and Cam have a contrasting small-scale intimacy that is enhanced by small woods, pasture and wetland vegetation. The river flow changes seasonally, nearly drying up completely in summer. Chalk rivers and their aquifers have long provided drinking water for East Anglian residents. The porous chalk results in limited surface water, but there are springlines where surface topography intercepts the aquifer or where groundwater emerges at less permeable horizons, such as the Totternhoe Stone at Ashwell. The clean spring water of the chalk has also had an influence on local industry, reflected in the local paper and parchment making tradition and frequent watercress beds.

Arable farming, as well as sheep grazing, have been significant since the prehistoric period; their importance has ebbed and flowed, as in the other chalk and limestone plateaux and downs of southern England. The smooth, rolling chalkland hills were historically grazed by sheep but the land use is now dominated by large-scale cereal production. The large fields are enclosed with low thorn, and characterised by often ‘gappy’ hedgerows and few trees. There is very little grazing pasture or livestock except within the small river valleys. Medieval deserted settlements testify to the shrinkage of arable cultivation after the 14th century, and there is an abundance of archaeological sites dating from the Neolithic Period. Also prominent are Anglo-Saxon linear dykes (Devil’s Dyke, Fleam Dyke and Brent Ditch), consisting of earthbanks with an adjacent ditch, which span the chalkland from the fen edge east of Cambridge to the wooded edge on the higher claylands. Devil’s Dyke is 11 km long, 6 m high and 4 m wide. A fourth, Heydon/ Bran Ditch near Fowlmere, has been almost completely lost to agriculture over time.

Roads are often lined with shelterbelts of beech, particularly to the eastern end, and these, together with hill-top clumps and copses, offer a little diversity. In the transitional area bordering the Brecks, pine belts begin to take over from beech. Ancient woodland and spring-fed meadows also feature here.

A significant influence around the southern edge of Newmarket has been that of horse-racing and stud farms, which have brought localised wealth and a manicured appearance to the landscape. The horse-racing industry has created a geometric grid, as the fences and shelterbelts of the stud farms provide a more enclosed pattern. This gives a well-wooded character within an area that extends in a broad sweep from the south-west (Six Mile Bottom) around to Moulton in the east.

On the fen edge in the north of the NCA is Chippenham Fen, an important wetland. Most sites of biodiversity interest today are remnants of the once extensive chalk grassland scattered throughout the natural area. The largest survivors are managed grasslands: the gallops at Newmarket and Royston; and the golf courses of the Gog Magog Hills and Therfield Heath. Fragments occur on roadside verges, in chalk pits such as Cherry Hinton, and along sections of the ancient linear dykes, Roman roads and disused railway lines.

Invertebrates such as the chalkhill blue butterfly are still associated with grasslands, but populations have generally declined with habitat fragmentation. Blue Lagoon is an old chalk and clay pit at Arlesey which has filled with water, but the surrounding land has become good semi-natural grassland. In the arable landscape there are still hotspots for the arable weeds ground pine and Venus’ looking-glass. In the Whittlesford area, the hollows formed by ground ice in periglacial conditions support grass-poly and fairy shrimp, one of the few British populations. There are still areas that support good populations of farmland birds, for example grey partridge around Royston, but generally there is a decline, for example in species such as turtle dove and skylark.

The village cores have a traditional appearance, with houses constructed of brick or ‘clunch’ under thatched roofs. Clunch is a soft chalk or limestone that hardens when dry but is prone to weathering erosion. To the east of Newmarket the villages tucked into the more undulating terrain are often Georgian, built of red brick and flint with slate, pegtile or thatched roofs. Further south there is a transitional zone around Saffron Walden (in the South Suffolk and North Essex Clayland NCA) onto the till, which supports a series of small attractive villages such as Barley, Barkway and the Chishills. Settlement has expanded as a result of significant 20th-century development. Letchworth Garden City is a planned garden city.

The chalklands are traversed by the prehistoric routeway, the Icknield Way, which is now a long-distance footpath offering recreational opportunity for locals and for seasoned ramblers, linking the Peddars Way and The Ridgeway National Trail. In The Icknield Way, nature writer Edward Thomas wrote about this ancient route. Grassland along the Icknield way is a stronghold of great pignut. The Fleam Dyke and Roman Road Walk is a 40-kilometre waymarked route, incorporating two of Cambridgeshire’s ancient linear sites.

Race days at Newmarket, and Duxford, now part of the Imperial War Museum, are significant leisure attractions, bringing thousands of visitors, many from long distances, while the iron-age hill fort at Wandlebury is now much-used locally for picnics and wildlife walks. A Cambridge student’s memory of visits to Wandlebury Ring and the Gog Magog Hills is described by E.M. Forster in The Longest Journey. Historically, the Chalk has been a significant source of raw materials for building purposes. Today, chalk is extracted for agricultural lime, as at Great Wilbraham, and notably for industrial whiting fillers at Steeple Morden quarry.

The landscape through time

During the Upper Cretaceous this area was dominated by marine environments. Locally, Cretaceous Gault Clay and Upper Greensand are overlain by the Chalk which forms the characteristic ridge of the NCA. The Chalk was deposited in a shallow, warm sea that covered much of Europe from 94 to 66 million years ago. It is made up of the calcareous microscopic remains of plankton and includes remains of fossils, such as ammonites, and characteristic flint nodules. After its deposition and uplift, and following the retreat of the Cretaceous seas, the Chalk was significantly eroded during the ice ages with the advance and retreat of ice during the Anglian glaciations, some 400,000 years ago. Glacial action ‘bulldozed’ large masses of chalk to form the chalk ridge to the west and east of Royston. During the most recent glaciations the area was not ice covered but was tundra-like during which time the dry valleys and swallow holes of the Chalk and the patterned ground of the nearby Brecks were formed.

In the post-glacial period, ‘early man’ would probably have cleared the more lightly forested area on the chalk escarpment. Fossil pollen records show significant changes from about 6,000 bp as the wildwood was cleared and pastoral farming became more widespread, leading to the open, treeless downland.

Spring-fed prehistoric settlements developed on the chalk downs (such as at Ashwell, Melbourn and Steeple Morden), on the terraces of the Cam valley and around exploitation sites where flint nodules used for tool making (for example at Duxford and Thriplow) were exposed in the upper strata of the Chalk. Neolithic and bronze-age ceremonial and funerary monuments are widespread across the Chalk (for instance at Therfield Heath), attesting to their long-term use for settlement and agriculture. Although distributed more widely across the chalklands, the Cam valley became a focal point for larger-scale iron-age and Roman settlements, such as at Great Chesterford (similar to the modern A11 route), where the rivers and new roads forged further connections, linking older routes with the new settlements on the clay plains or gravel terraces. Ermine Street, the London (Londinium) to York (Eburacum) road, passed by the Chalk-based settlement at Royston, before crossing the clays to the north to reach Godmanchester. Four great linear dykes (Devil’s Dyke, Fleam Dyke, Brent Ditch and Heydon/Bran Ditch) were built by the Saxons to control movement along the Icknield Way between the 5th and 7th centuries ad.

Medieval moated sites, park lands and nucleated villages are distinctive features of medieval settlement on the Chalk, many of which are preserved in the grounds of later country estates (for example Barrington, Sawston and Fulbourn), and many are also Scheduled Monuments.

The light chalk soils were well suited to arable farming, which contracted in the 14th and 15th centuries. Extensive unenclosed downland pasture remained until the late 18th century, but from this period an increasing area was enclosed and returned to the plough. Dry heaths were burnt before cultivation in the area around Dullingham, as described by agricultural writer Arthur Young in 1805. The cleared areas would have either become grazing land or been cropped. As productivity fell, the fields were abandoned and allowed to revert to woodland or they became pasture. On the chalky soils, calcareous grassland would have developed, with sheep preventing the return to woodland. An increasing use of manure from yard-fed cattle and of artificial fertilisers characterised the 19th and early 20th centuries. Isolated white- or yellow-brick farmhouses were built on the hill tops, mainly in the 19th century, reflecting this period of agricultural growth.

Settlement occurred along the sides of the river valleys, where small villages were founded, such as Linton. Sheep farming survived well into the 20th century; since then agricultural land has been used to grow barley and other high-value crops such as flax and oilseed rape despite the thin, poor soils.

The clean spring water of the chalk has had an influence on local industry, such as watercress beds and the paper industry at Sawston. Much local chalk and ‘clunch’ quarrying took place, particularly at villages on the fen edge, for example at Steeple Morden. Until recently Barrington quarry provided huge quantities of chalk and clay for cement making, and Cherry Hinton provided builder’s lime and also the chalk ‘clunch’ used to build Cambridge.

Cambridge, outside this NCA but of influence, developed as an internationally significant university city in the medieval period, not substantially expanding out of its medieval boundaries until the 19th century; and a market was established at Newmarket in the 13th century (hence the name). Horse-racing’s history in Newmarket can be traced back to at least the reign of King James I. With its paddocks and gallops, it has been a centre of racing and horsebreeding excellence since the early 17th century. By the early 18th century the thoroughbred racehorse was the aristocratic status symbol par excellence and people crowded to the racecourse on top of the rolling downland. (The embankment, or vallum, of Devil’s Dyke, which divides the July and Rowley Mile courses, provides a viewing platform.)

Horse-racing and golf courses have safeguarded chalk grasslands, but species diversity has been lost. Great bustard was last seen nearly 200 years ago and used to breed near Newmarket. Although chalk grassland is present today, the number of individual species it supports is reduced; for example, the chalkhill blue butterfly is in decline.

In the 20th century villages have maintained a historic core but some, especially those with a railway station, have become commuter villages, such as Foxton and Meldreth. Letchworth Garden City, the world’s first garden city, was established in the 20th century, and other towns grew substantially in the latter part of that century.

Cambridge is one of the fastest-growing cities in Western Europe and its expanding southern developments in the greenbelt influence the built-up character of this area. The railway across the south Midlands linking East Anglia with the West Country by way of the cities of Cambridge and Oxford was closed amid great controversy in the 1970s.

Since the 1950s, tranquillity has declined around the urban centres and – the transport routes, especially around the M11, A505 and A10. Several wind farms have been built in the last five years which have a visual impact on the landscape.

Post-war enlargement of fields by hedgerow removal saw the creation of open fields, particularly concentrated in Hertfordshire and Bedfordshire, although some places, such as Bygrave, were never enclosed. The area is still important for arable weeds, including grass-poly and Venus’ looking-glass; with the intensification of agriculture in the last 50 years there has been a large decline in species numbers.

The NCA has experienced dramatic land use changes in past and recent times. These changes have influenced the present nature, location and extent of the wildlife resource. There is recognition of the importance of the remnant habitats, sometimes confined to roadside verges; the small scale of these sites makes management – and therefore maintenance of biodiversity value – very difficult.