Exploring our boundaries
The Blackdown Hills AONB is known for its extensive and connected field boundary network. In fact, this is one of the special qualities that led to the Blackdown Hills’ designation as an Area of Outstanding Natural Beauty.
In recent months, we have been a working on a case study to explore some of the field boundaries and linear landscape features of the Blackdown Hills AONB, to assess their heritage value and the benefits they provide to people, and to evaluate the role play in our landscape.
The project’s final report – An integrated approach to valuing environmental capital and services (boundaries and linear landscape features) – is now available to download.
Assessing the value of historic boundaries using modern approaches
Working in partnership with Devon County Council’s Historic Environment team and other partners, Blackdown Hills AONB secured £15,000 from Historic England to undertake this case study.
The project was one of nine national pilot studies, funded by Historic England, to explore how the heritage sector might engage more fruitfully with ‘natural capital’ and ‘ecosystem services’ approaches, with a view to developing national guidelines.
‘Natural capital’ is defined as the world’s stock of natural resources, which includes geology, soils, air, water and all living organisms. ‘Ecosystem services’ are the many and varied benefits that humans freely gain from the natural environment and from properly-functioning ecosystems.
The natural capital value of these features had not previously been measured and indeed there is little information on the extent and condition of the resource overall.
The study’s findings
Demonstrating the link between the historic environment and the natural capital stock is challenging, as it relies on having comprehensive datasets that are often not available at the correct resolution. In this study, pre-designation archaeological surveys and a recent National Mapping Programme survey in the Blackdown Hills meant that we could use quite detailed historical environment information. Yet the biological data we had was often too coarse a scale for meaningful analysis.
For this case study, we assessed the field boundaries in four study areas chosen from across the Blackdown Hills AONB, each measuring 4 km sq in size. We assessed their values in terms of natural capital and the ecosystem services they provide, for example biomass, flood alleviation, access and recreation, biodiversity and cultural heritage.
The study highlighted that there is a significant amount of natural capital stock in the Blackdown Hills AONB and there is evidence that the natural capital is currently undervalued. The AONB’s extensive field boundary networks (predominantly banks with hedges) are well connected, many intact and with variable numbers of hedgerow trees. In one of the 4 sq km study areas, close to Hemyock, we measured 78km of field boundaries, 74km of which are hedgerows!
We were able to assess two of the four study areas in relation to the monetary value of the ecosystem services they provide. It was evident that the extensive field boundary networks of Blackdown Hills AONB have significant value in terms of ecosystem services.
Most of the hedges in the four study areas are of considerable historic interest. Their thick, sinuous nature is typical of landscapes of medieval origin.
When biological, historic and cultural heritage assets are considered together, their value in terms of natural capital stock and ecosystem services becomes greater than the sum of its parts. For all the study areas we looked at, we found a significant association between the field boundaries and heritage assets recorded on the Historic Environment Record.
We evaluated the natural capital resource in areas of different Historic Landscape Character. Some Historic Landscape Character types within the study areas are richer in natural capital than others and provide more benefit to society. There are clear differences between the medieval enclosures, typically found along river valleys, and the parliamentary enclosures along the plateaux tops of the Blackdown Hills. In medieval enclosures the field boundaries tend to be wider, denser and of a sinuous nature, giving them a greater natural capital value. There were commonalities too. Across all the Historic Landscape Character types, the Blackdown Hills AONB is replete with hedgerow trees and small copses.
Historic England will collate the Blackdown Hills case study along with the others and use it to produce guidance for the heritage sector on how to best incorporate historic and cultural heritage into ‘natural’ capital assessments. It is part of a national initiative to support the heritage sector in engaging with natural capital and ecosystem services methodologies, and to protect the historic environment within future environmental policy.
The boundaries of the Blackdown Hills
The Blackdown Hills is an isolated, unspoilt rural area and remains relatively undisturbed by modern development and so ancient landscape features, special habitats, historical and archaeological remains have survived intact. The traditional pattern of villages, hamlets, paths and roads remains largely unchanged and there is an identifiable and characteristic vernacular, pastoral landscape. There is a diversity of landscape patterns.
Although the scenery is immensely varied, some features are repeated. Ancient, species-rich hedgerows delineate the fields and define the character of the landscape, enclosing narrow twisting lanes. There are long views over field-patterned landscapes. The high plateau is dissected by steep valleys, supporting a patchwork of woodland and heath, and fine avenues of beech along the ridge. The history of medieval and parliamentary enclosures has resulted in an individual, patchwork landscape of small fields in the valleys and larger fields with straight hedges on the plateau.
The landscapes of the Blackdown Hills have been created by the interplay of people and the land over the centuries. There are significant concentrations of early prehistoric evidence: since prehistoric times those who lived here have left evidence of their activities that can still been seen today; tools from the Neolithic, Bronze Age barrows on the ridge tops and spectacular Iron Age hillforts that dominate the surrounding lowlands. The Romans left their villas and extensive evidence of iron working. The pattern of fields medieval, and in places prehistoric, in its origins. The ancient woodlands and the Royal hunting forest of Neroche are also survivals of the medieval period. Parliamentary enclosure of the commons, culminating in the 19th century, created the regular fields and straight roads of the plateau tops. Three airfields on the plateau played important roles in World War Two. Since that time there has been a substantial loss of hedgerows and orchards to meet the needs of modern agriculture; simplifying parts of the landscape and masking their early origins.
The biodiversity of the Blackdown Hills is one of its greatest assets. The unique geology and landscape patterns of the area have combined with traditional management to support a rich diversity of habitats and species. This immense variety, with patches of valuable habitat scattered throughout the landscape, is notable; these include flower-rich meadows, ancient hedgerows, spring line mire, wet woodland, heathland, calcareous grassland, ancient woodland, fen and bog. Bees, butterflies, birds, bats and many other animals, some nationally scarce, thrive in the Blackdown Hills, feeding and breeding in the habitats the area provides. These habitats and wildlife bring colour, texture, sound and life to the landscape, epitomising the mental picture of the ‘English Countryside’, which has long since disappeared elsewhere.
Sharing what we’ve learnt
We will, of course, use what we’ve learnt in this study to inform our own work, but we have also been sharing our findings with a variety of other organisations and individuals. The study has enabled us to better appreciate the value of our field boundaries. It will help us to work with others to continue to research the value of these important historic assets, manage them appropriately, and benefit from the ecosystem services they provide.
