115 - Thames Valley : Natural Capital and Key Ecosystem Services

Introduction

The Thames Valley 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 Thames Valley NCA is contained in the ‘Analysis’ section 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.

Natural Capital Atlas Profiles

The following Natural Capital Atlas Profiles cover counties within this NCA:
 

• 2: Berkshire
• 3: Buckinghamshire
• 15: Greater London
• 19: Hertfordshire
• 31: Oxfordshire
• 37: Surrey

Provisioning services (food, fibre and water supply)

Food provision: The gravel beds of the upper tideway are an important nursery ground for several species of North Sea fish, notably flounder. The spread of urban areas has reduced agricultural land within the NCA to under 25 per cent per cent. The NCA now produces a limited range of crops and livestock.

Biomass energy: The potential yield for miscanthus is predominantly high throughout, while for short rotation coppice it is predominantly medium. The existing woodland cover (13 per cent per cent) offers potential for biomass through managing woodland, although woodland is concentrated in the north of the area and is missing from much of the NCA.

Water availability: The north of the NCA is underlain by the edge of the Chilterns chalk aquifer and chalk streams feed into the water supply. Overall, the area is under considerable pressure to supply London and the surrounding area. Water sources have been assessed as either over-abstracted or having no availability for abstraction. Most of the area’s demand for water is met by the Thames, with most licences being for public water supply. The largest single licence is used to supply the Lower Thames reservoirs, to meet the water needs of London. Of all the rivers in the NCA, only the Loddon (east of Reading) is classed as having water available for abstraction. For information regarding the current state of water availability within this NCA, refer to the Environment Agency (Abstraction Licensing Strategy).

Genetic diversity: The NCA contains the Royal Botanic Gardens at Kew, which were awarded UNESCO World Heritage Site status in 2003 – partly for their uninterrupted role as a centre of plant research, but also for their unique collections of living and stored material. The Great Vine at Hampton Court Palace is the oldest and largest known vine in the world. A few remnant orchards also contain the genetic material of local fruit varieties, such as Cox’s Orange Pippin, first developed in this area.

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

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).

Regulating water flow: Flood regulation is a key issue throughout, with flood risk affecting numerous settlements. Locks and weirs maintain water levels along the Thames, and can be fully opened when flows increase, to minimise impact. The Thames Catchment Flood Management Plan identifies that further action needs to be taken to reduce flood risk throughout the area, with policies that include measures to store water or manage run-off while also providing environmental benefits.

Cultural services (inspiration, education and wellbeing)

Sense of place/inspiration: A sense of place is supported by the presence of water throughout the area, in the form of the River Thames and its tributaries, as well as numerous open waterbodies that are the result of gravel workings and reservoirs. The view of St Paul’s cathedral from King Henry’s Mound in Richmond Park, created in 1710, is a protected view, an example of the important connections between this area and the capital. The landscape is described in the works of some of the most famous writers in English literature, including Shakespeare, Jerome K Jerome and Sir Walter Scott. It has also inspired great artists such as J M W Turner and Joshua Reynolds, as well as poets including Alexander Pope. William Wordsworth described the nightingales (for which the area was famed) as ‘the quire of Richmond Hill, chanting with indefatigable bill’. The ‘Arcadian Thames’ area around Richmond and Twickenham is the birthplace of the English Landscape movement. Walpole’s house at Strawberry Hill is internationally recognised as the finest surviving example of Georgian ‘gothic’ and an inspiration for the Gothic Revival. The historic parkland, veteran trees and rich biodiversity reflect the NCA’s long history as an area of recreation and escape on the edge of London.

Sense of history: Historic buildings include large houses set within their own grounds, along with traditional black timber-framed farm buildings. Windsor Castle sits atop its chalk outcrop by the Thames, while other internationally renowned buildings along the river include Hampton Court Palace and the Palm House at Kew. The river is closely associated with important historic and cultural events, including the attachment of the Great Seal to Magna Carta at Runnymede in 1215, and the death of Elizabeth I at Richmond. Historic parklands, such as Dropmore, Langley and Richmond, are highly distinctive features, as are characteristic veteran pollards – important elements in fields, hedgerows and parkland.

Recreation: Recreation is supported by over 1,000 km of rights of way (a density of 1.19 km per km2), including the Thames Path National Trail, as well as by the area’s parklands, greens, commons, woodlands and waterbodies (with private recreation evident in numerous golf courses throughout the area). Sailing, watersports and angling are all popular pursuits on the River Thames, and on many reservoirs and other waterbodies. Commons and other open access land provide recreational opportunities in places such as Chertsey Meads and Staines Moor, along with three of London’s National Nature Reserves: Ruislip Woods, Burnham Beeches and Richmond Park. There are also several accessible historic parks in the north, including Denham and Black Park Country Parks. Most of the 108-kilometre Thames Valley National Cycle Route between London and Oxford runs through the NCA, and National Cycle Route 61 runs along the length of the Jubilee River. All of the above contribute to the health and wellbeing of the large population of this predominantly urban NCA.

Biodiversity: The diversity of geology has resulted in a variety of habitats and land uses across the area, including heathland over acidic sands north of Slough, large areas of woodland over the clays (notably Windsor Forest in the south and Burnham Beeches in the north), extensive gravel workings along the flood plain and an outcrop of chalk at Windsor. The meadows and pastures of the river valleys are important for wading birds: lapwing, snipe, curlew and redshank breed in the area, and in winter large numbers of lapwing and golden plover are attracted to the flood plain. Scrub and woodland near water is important for songbirds, notably nightingale. Biodiversity Action Plan (BAP) priority habitat covers around 6 per cent per cent of the NCA: this includes over 2,500 ha of woodland and around 2,000 ha of other wetland habitat, as well as small but important areas of lowland heathland. Over 800 ha of waterbodies within the area are internationally designated as SPA and Ramsar sites for their importance for various wildfowl, for example Northern shoveler, gadwall and 7.8 per cent of the British population of overwintering smew. There are four SAC covering over 3,000 ha and noted particularly for invertebrate interest. Around 7,000 ha of historic parkland across the NCA provide a rich variety of habitats. Windsor Great Park is widely regarded as the foremost site in the United Kingdom for invertebrates and fungi associated with wood pasture and parkland. A small part of the Thames Basin Heaths SPA buffer zone lies within the NCA, south of Windsor.

Geodiversity: Geodiversity strongly influences the character of the area, including its topography, habitat distribution and land use. Most notable are the influence on water supply of underlying sediments and structures, and the numerous examples of sand and gravel extraction across the area. The area is particularly important for understanding landscape evolution over the last 400,000 years: this period saw the maximum advance of the Anglian ice sheet, forcing the River Thames southwards into its current course. The subsequent evolution of the Thames is documented in the complex sequence of river terraces, which are also intimately linked to understanding the archaeological history of the area.