National Character Area 116

Berkshire and Marlborough Downs - Natural Capital and Key Ecosystem Services

Introduction

The Berkshire and Marlborough Downs NCA provides a wide range of benefits to society. Each is derived from the attributes and processes (both natural and cultural features) within the area. These benefits are known collectively as ‘ecosystem services’. The predominant services are summarised below. Further information on ecosystem services provided in the Berkshire and Marlborough Downs NCA is contained in the ‘Analysis’ section of this website.

Note: The natural capital in this NCA is mapped below. This displays more recent national and publicly available data sets as used within Natural England’s 2020 Natural Capital Atlas Profiles.

The predominant ecosystem services in this NCA are also summarised below. The text contained in this section is based on the previous NCA profiles in 2014, and so is not entirely current. Further information on ecosystem services provided in the North Northumberland Coastal Plain NCA is contained in the Analysis: Ecosystem Services page of this website.

What is Natural Capital?

Natural capital means “the elements of nature that directly or indirectly produce value to people, including ecosystems, species, freshwater, land, minerals, the air and oceans, as well as natural processes and functions” (Natural Capital Committee, 2017).

It is helpful to consider natural capital in the form of a logic chain that represents the links between ecosystem assets, services, benefits and value to people. The figure below displays that logic chain. The quantity and quality of ecosystem assets (woodland, bogs, etc) support different types of ecosystem services, such as carbon sequestration or water filtration. These ecosystem services then provide different benefits to society, providing value for people. The figure also shows how management interventions, as well as pressures and drivers of change, influence this chain. Other capital inputs are also often needed for people to obtain the benefits from ecosystem services (a simple example is the processing of trees to produce wood products).

As an example, an area of woodland (ecosystem asset) may reduce air pollution created by traffic on a nearby road. This woodland is therefore improving air quality (ecosystem service) in the local area which results in cleaner air and improved health in the adjacent residential street (benefit). This cleaner air has a value because we know it impacts the health and wellbeing of communities.

Sometimes for ease of understanding, economic framing is used to give these benefits a monetary value. The figure below shows how natural capital assets support the provision of ecosystem services, benefits and value. The roots of the tree show how aspects of asset quality are critical to the provision of ecosystem services. The roots also show that geodiversity underpins the ecosystem assets and therefore the ecosystem services and benefits they can provide. It is important to remember that this diagram, and natural capital frameworks more generally, are a simplification of how nature works in practice.

Natural Capital within this NCA

In 2018, Natural England published ‘Natural Capital Indicators: for defining and measuring change in natural capital’ (Lusardi et al., 2018). This report identified key properties of the natural environment vital for the long-term sustainability of benefits, which can act as indicators of change.

These indicators are designed to inform our understanding of the state of our natural assets. The indicators highlight the importance of our natural assets for delivering which ecosystem service and the benefits they provide for society. The indicators and datasets identified in Natural England’s Natural Capital Indicators Project provide the foundation for the Natural Capital Atlas Profiles.

Natural England’s Natural Capital Atlas Profiles provide an “off the shelf” natural capital evidence base for each county or city region. They have a wide variety of uses with more information in the How to Start Using Your Natural Capital Atlas.

The Natural Capital indicators are presented on the map below by broad asset theme, displaying the natural capital within the NCA.

It is noted that not all indicators listed within the Natural Capital Atlas Profiles are included within the map as data is not yet available to measure them. Refer to the “Indicator Gaps and Limitations” of the Natural Capital Atlas Profiles for further information.

Note that numbers and figures in the body of the text are based on the 2014 profiles, unless otherwise stated.

Provisioning services (food, fibre and water supply)

Food provision: Grade 1 and 2 agricultural land across the northern plateau, in valley bottoms and in the Vale of Pewsey offers optimal conditions for growing. Light, chalk soils can be easily cultivated and, consequently, arable farming dominates across the high Downs. Arable crops and remnant fruit orchards are present in the Vale of Pewsey across well-watered, fertile Grade 1 land. The remainder of the NCA is Grade 3 and can be put to grass or cropping as circumstances dictate. Dairying is largely confined to areas in the Vale of Pewsey and in the valleys of the Berkshire Downs. The local brewing industry was founded on nearby supplies of good quality barley and clean water.

Water availability: Underlain by the Chalk and Upper Greensand, the entire NCA comprises a major aquifer. The majority of the aquifer is unconfined so the potential for recharge is high. Swallow holes and freely draining soils further support infiltration. Water is largely abstracted directly from the aquifer, rather than from surface waters, for public water supplies and, to a lesser extent, for agriculture and fish farming. Water is also exported out of the NCA from Axford on the River Kennet to the major urban and growth area of Swindon.

In addition to human consumption, water availability is important for the functioning of water-dependent features that are significant in this NCA: four SAC, chalk streams, the Kennet and Avon Canal and distinctive chalk stream heritage features including flood meadows and mills. The Vale of Pewsey is noted for its numerous watercourses which contrast with the dry valleys and low flows of chalk streams in the Downs. For information regarding the current state of water availability within this NCA, refer to the Environment Agency (Abstraction Licensing Strategy).

Regulating services (water purification, air quality maintenance and climate regulation)

Regulating soil erosion: Soil conservation is achieved where there is permanent grassland and by vegetated strips in arable landscapes such as woodlands, hedgerows and grassland buffers. The intrinsic vulnerability to erosion is greatest across the arable downlands where large fields lie on slopes and where thin soils are cultivated.

Prevention of soil erosion is critical to good water quality in the major aquifer and to the conservation of valued water-dependent features including four SAC, chalk streams and fish populations, including those managed for angling interests, as well continuing agricultural productivity.

Regulating water quality:For information regarding the current state of water quality within this NCA, refer to the Environment Agency (Draft river basin management plan maps).

Groundwater quality is critical in this NCA since the bedrock functions as a major aquifer from which water is drawn for human consumption. Unpolluted water is also important in the conservation of chalk stream biodiversity and of healthy fish stocks. Characteristic chalk stream plants such as the water crow-foots and fish such as wild brown trout require water devoid of chemical pollutants and sediments.

Regulating water flow: Groundwater flows within the chalk aquifer are predominantly in the direction of the London Basin to the south and east but, along the northern escarpment, groundwater flows northwards towards the vales. Surface water flows fall into four catchments and watercourses on the Chalk and Upper Greensand are also fed by groundwater. The River Lambourn has a near-natural flow regime but other chalk watercourses have exhibited low flows and dry headwaters attributable to abstraction.

Flow is important for water-dependent features characteristic of this NCA. Adequate flow is required to scour the riverbeds to provide suitable spawning habitat for fish such as brook lamprey and bullhead which are subject to SAC designation in the rivers Avon and Lambourn. Flow regimes supporting the breeding of game fish such as brown trout are of significance to fishing interests. Chalk stream heritage assets, including flood meadows and mills, are reliant on water flows being maintained at reasonable levels.

Flooding by groundwater and surface water has been localised in the past. Settlements such as Compton have been affected.

Cultural services (inspiration, education and wellbeing)

Sense of place/inspiration: The majority of the area is designated as an AONB, recognising the special scenic and natural qualities of the landscape. Landform is prominent and large scale and includes well-known features such as the ‘Manger’ and characteristic chalk scenery. Nationally prominent artists such as Eric Ravilious, Paul Nash and David Inshaw and writers such as Thomas Hardy and Richard Jefferies have been inspired by this landscape.

Famous landmarks and visitor destinations include Avebury stone circle, Uffington chalk-cut horse figure, Silbury Hill, the Kennet and Avon Canal and the Ridgeway National Trail, all attracting large numbers of visitors. Distinguished historians, archaeologists and antiquarians are associated with Avebury and surrounding monuments, including John Aubrey, William Stukeley and Sir Richard Colt Hoare. Chalk streams in the Downs have also long attracted settlement and are associated with historical buildings and monuments.

The Lambourn Valley is a centre for the horse-racing industry, second only to Newmarket.

The Vale of Pewsey and Vale of Ham form a discrete, low-lying corridor between the Downs and the escarpments of the NCAs to the south. In contrast to the Downs, there are densely scattered villages, numerous watercourses and ditches, and remnant orchards.

Sense of history: This is a visibly ancient landscape which has for centuries attracted antiquarian interest, with more than 400 Scheduled Monuments and the Avebury World Heritage Site dating from the Neolithic period and extending over 25 km2. The World Heritage Site is a focus of research for this period. Historical features represent the various eras of civilisation, including more recent pillboxes and other anti-invasion defences from the Second World War.

The sarsen stone ‘trains’ and periglacial landforms extend the time-depth of this landscape further as relic features unmodified since the glaciations of the Quaternary.

Many monuments and modified landforms are prominent on the skyline and several emblematic sites are accessible to the public along the Ridgeway or on open access land. Avebury and other monuments are well documented in academic literature. The fieldscapes and farmsteads of the area also provide a sense of the continuity of farming, where the importance of arable cropping and cattle is represented in large barns and cattle yards.

Biodiversity: Six SAC and two NNRs are located in this NCA, including long stretches of chalk stream. Just over 2,000 ha are designated Sites of Special Scientific Interest (SSSI) and there are 442 Local Wildlife Sites. Savernake Forest is a large SSSI at approximately 900 ha. The River Lambourn SSSI is a rare example of a relatively unmodified chalk stream18. There are complexes of habitat which represent valuable core areas or connected sites in the ecological network, in particular clusters of chalk grasslands on the escarpments. Special flora and fauna include stone curlew, rare lichens, bryophytes and arable plants, and early gentian. Biodiversity associated with chalk grassland is accessible as open access land while linear routes provide limited public access to arable and woodland biodiversity.

Geodiversity: There are seven SSSI with geodiversity interest and seven Local Geological Sites. Chalk landform is a defining feature of this NCA, involving dramatic and extensive escarpments, high hills and steep valleys. Well-known features associated with the Chalk include cut figures on the escarpments, the combe known as the ‘Manger’ and the plain upon which Avebury stone circle is sited. Flint, hard chalks and sarsens have been traditionally used to create distinctive buildings. Prehistoric stone circles and barrows are often constructed from uncut sarsen stones. The sarsen stone ‘trains’ on Fyfield Down and Piggledene are protected by SSSI designation for their rarity as relics of Quaternary landscape but sarsens are also found at field edges or scattered in grasslands. The Chalk and Upper Greensand bedrocks are also important for their aquifer function.