National Character Area 60

Mersey Valley - Natural Capital and Key Ecosystem Services

Introduction

The Mersey 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 Mersey Valley 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: To the north of the River Mersey, agriculture is dominated by arable cultivation and to the south pasture becomes more frequent, with mixed farming (arable and dairying) predominating. On the dark, rich peaty soils of the former mosses, farming is mixed. Over 30 per cent of this NCA is Grade 1 or Grade 2 agricultural land. Sustainable agricultural practices can contribute to the production of high-quality food.

Biomass energy: There may be some opportunities within the Mersey Valley NCA for both short rotation coppice (SRC) and miscanthus to be accommodated without significant landscape effects, due to the low- lying valley character, the complex land use pattern including arable and mixed farmland, and the existing urban influence on the landscape. Power stations locally are exploring ways of achieving more energy production through use of renewable biomass sources, and their decisions may have an impact on the crops grown in close proximity. Provision of SRC and miscanthus as a source of renewable energy could contribute towards addressing climate regulation. There are opportunities from arboricultural arisings and waste wood as well as small amounts from existing woodland including the newer community woodlands.

Water availability: Surface water abstraction within the NCA is heavily dominated by industrial abstraction, and to a lesser extent, agriculture. There are no surface water abstractions for public water supply primarily due to water quality issues. In contrast, the main abstraction from groundwater is for domestic water supply. The Triassic sandstone forms an important aquifer. 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)

Climate regulation: Large areas of soils with a high carbon content occur, reflecting the NCA’s soil types which contain organic-rich or peaty layers. The peaty and organic soils of the NCA have an important role in carbon sequestration and storage. Adopting management options that reduce the soil disturbance, erosion and oxidation is likely to result in retaining carbon stores. Carbon storage and sequestration are provided by the NCA’s woodland, mudflats, salt marsh and marine sediments. Positive management of wetland, woodland and estuarine habitats could result in carbon sequestration, and woodland creation in suitable locations could further increase this.

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: The River Mersey flows west through the NCA and enters the Irish Sea at Liverpool Bay. The Mersey is tidally influenced downstream from Howley Weir (Warrington). The catchment is largely low- lying with a few steeper areas. The catchment has been heavily modified for industrial purposes, and this has affected the natural response of river flows. The Manchester Ship Canal, which was built for navigation, reduces fluvial flood risk through Warrington. The response to rainfall is generally slow but is much faster for some of the smaller tributaries flowing through urbanised areas. Some properties are at risk of fluvial flooding, including in Warrington. Where rivers discharge into an estuary, such as the River Weaver at Runcorn, there can potentially be either a fluvial or tidal flood event or both at the same time. Wetlands, woodlands and other habitats can alleviate speed of run-off.

Regulating coastal flooding and erosion: Intertidal mudflats/sand flats and salt marsh vegetation in the Mersey Estuary are subject to tidal flooding. Intertidal habitats such as mudflats/sand flats and salt marsh effectively absorb the energy of waves, and thus provide a natural defence against sea level rise and flooding. These habitats are valuable for control of sea flooding but are under threat due to sea level rise, and the consequent coastal squeeze. The process of erosion and accretion on mudflats/sand flats and salt marshes is necessary to maintain a succession of diverse habitats. For information regarding current shoreline management within this NCA, refer to the Environment Agency (Shoreline management plans).

Cultural services (inspiration, education and wellbeing)

Sense of place/inspiration: Senses of inspiration and escapism may be provided by the broad panoramic views to the west across the Mersey Estuary. The many views of the extensive industrial complexes and docks, lit up at night, can also be dramatic and inspirational. The natural heritage of the river valley is important, being close to where people live as well as providing valuable wildlife corridors, and contributes to providing a sense of place and inspiration. Communities also value their local green spaces as places of local distinctiveness that provide opportunities to engage with nature close to where they live and work, and that helps to encourage a sense of community.

Sense of history: The history of the landscape is largely associated with the River Mersey and Estuary, including evidence of strategic crossing points in the form of ancient fortifications at Warrington. Areas of peat have the potential to preserve organic remains, such as pollen. There is extensive industrial heritage, particularly linking to the development of the ports, trade, industry, canals and railways. There is evidence of sites defending the Mersey Valley during the Second World War as well as Cold War sites. Other aspects of history likely to be particularly evident to the public are the reclaimed mosslands and the Registered Parks and Gardens of Dunham Massey and Castle Park (Frodsham).

Recreation: There are large populations locally, both within the towns of the Mersey Valley and the two adjacent conurbations. Local woodlands and the two Community Forests have generated local interest to increase woodland and other habitats, create wildlife corridors and provide access for people. Local Nature Reserves and country parks also provide opportunities for people to enjoy the natural environment. Communities value their local green spaces as places of local distinctiveness that provide opportunities to engage with nature close to where they live and work, to improve physical and mental health and encourage a sense of community.

Biodiversity: The Mersey Estuary is of international significance, with large areas designated as a Ramsar site and as an SPA for its extensive intertidal habitats such as mudflats and internationally important bird populations. Examples of degraded raised bog habitat have survived on the Mersey flood plain, including the Manchester Mosses SAC. The ponds at Rixton Clay Pits SAC provide breeding sites for an important population of great crested newts. Other wetland sites include Woolston Eyes SSSI, where lagoons set aside to receive dredging from the Manchester Ship Canal form large areas of open water, reedbed and scrub vegetation.

Geodiversity: Peat-forming bogs and the dynamic intertidal environments are both examples of active geomorphological processes. Geological exposures, for example of sandstone sequences, make an important contribution to understanding of the origin and geological development of the NCA.