Lowland heath is characterized by dwarf shrubs such as heather and cross-leaved heath and is generally found below 300m in altitude. In the absence of an agreed altitudinal cut-off between lowland and upland heath in the north of England, however, and in order to define lowland heath for monitoring purposes, heathland outside the North Pennines Natural Area is taken to be lowland and vice versa.
In good condition, lowland heathland consists of a dwarf shrub layer of varying heights and structure with areas of bare ground, gorse, bogs and open water as well as scattered trees and scrub. This diversity of habitat supports a wide range of characteristic species including rare invertebrates, reptiles, flowering plants, mosses, liverworts and lichens, which are in turn, an important factor in determining habitat quality.
Lowland heath is a priority for nature conservation because it is a rare and threatened habitat. In England only one sixth of the heathland present in 1800 now remains. There are around 95,000 hectares of lowland heathland in the UK with 61% found in England. The most significant areas are in the south and south-west, Staffordshire, East Anglia, and south and west Wales. The UK has an important proportion (about 20%) of the international total of this habitat.
Durham is close to the northern limit of the habitat and as such it is relatively rare in the county. Under previous definitions around 114 ha were said to exist in County Durham and southern Tyne and Wear (Brodin 2001), the largest single site being Waldridge Fell in Chester-le-Street . This definition clearly excluded large areas of heath near to the 300m altitudinal limit, such as Hedleyhope Fell which lies between the 170m and 300m contours, and which was recently acquired by the Durham Wildlife Trust, or Knitsely Fell between 150m and 270m.
Large sites such as Hedleyhope, Knitsley and Waldridge Fells are also the most diverse, supporting a range of habitats including mires, scrub, acid grassland and areas dominated by heather & bracken. However large sites are now the exception and most sites are small and highly fragmented within the Durham portion of the Northumbrian Coal Measures Natural Area.
Lowland Acid Grassland
In many parts of the Northumbrian Coal Measures where heath has disappeared, fragments of lowland acid grassland remain, isolated from the heathland mosaic. Lowland acid grassland is also known to have developed on drained areas of floodplain meadow in Gateshead , although reasons for this are not clear. Lowland acid grassland is not necessarily species rich, but has a characteristic suite of species including heath bedstraw, heath woodrush, tormentil and wavy hair grass. It is a rare and fragmented resource in the Durham BAP area and therefore a priority habitat in its own right.
Some Brownfield sites in the Northumbrian Coal Measures, such as Tanfield Railway sidings in Gateshead , are developing naturally towards lowland heath or acid grassland.
Areas of acid grassland within heath can be botanically important in their own right, and a number of these grasslands support significant numbers of waxcap and related fungi. (see Waxcap Grassland action plan).
DBAP species that should benefit from this plan include the Small pearl-bordered fritillary. Large colonies were once found at Waldridge fell, but now only survive in heathland areas at around 300m altitude. Green hairstreak is found at Waldridge and Hedleyhope Fells, a butterfly that relies on bilberry as its larval foodplant. Nightjars prefer bare patches in heathland as nesting sites. In Durham the largest population is in Hamsterley Forest but it is thought there are smaller populations scattered throughout the county.
Adders are thought to be widespread throughout the county with Pow Hill being listed as a particularly good area for the species. Slow worms are also relatively widespread but at a much lower population level than adders, it is thought that Waldridge Fell may hold a significant population.
Current or recent activity
Durham Wildlife Trust acquired Hedleyhope Fell, 215ha of heathland near Tow Law. Extensive surveys were undertaken in 2005/06 and a management plan is currently being developed.
Durham County Council has undertaken extensive work to restore heathland at Chapman's Well, near Anfield Plain, including bracken and gorse removal and heather introduction. Areas of the SSSI have been cleared and replanted with 800 heather plants. Twenty ha of grassland outside of the SSSI have been cut and seeded with heather (2003-2006).
Durham County Council in association with the Acorn Trust has re-created heathland along the route of the new Bowes Railway cyclepath - 7 plots averaging 25 m2.
Gateshead Council's Burdon Moor restoration project has been ongoing since 2000. A fifteen ha reclaimed opencast site on an area of former heath was bought with the aim of heathland reclamation. Progress to date includes: seeding with heather and heathland grasses; planting of individual heather plants; sulphur treatment to lower soil pH; creation of shallow scrapes to form seasonal and permanent wetlands; small areas of tree planting; interpretation. (In association with Great North Forest, Northumbrian Water Environment Trust and the Countryside Agency.)
Gateshead Council's creation of 2.4 ha of lowland heath as part of the reclamation of the Watergate colliery site to form Watergate Forest Park has taken place since 1999 in association with One North East and ADAS.
Derwentside District Council established a heather nursery between 1999 and 2004 for the propagation of locally-sourced heather seedlings.
Durham County Council manage several lowland heathland sites. Works at Waldridge Fell SSSI have recently included birch removal and improvements of heather habitat. Quaking Houses Fell was designated as a County Wildlife Site in 1999.
Intensive agricultural practices such as overgrazing and agricultural improvement.
Nutrient enrichment- especially from intensive livestock farming practices.
Fragmentation and disturbance from developments such as housing and road construction and from mineral extraction.
Deliberate fire lighting by vandals.
Intensive recreational pressures.
Scrub and tree encroachment, due to a lack of suitable grazing.
More information / references
Andrews, J. (1990). Management of lowland heathlands for wildlife British Wildlife 1 pp. 336-346
English Nature (1996). Management of bare ground on dry grasslands and heathlands Peterborough
Lane, A. (1992). Practical Conservation- grasslands, heaths and moors (The Open University in association with the Nature Conservancy Council). Open University: London
Michael, N. (1993). The lowland heathland management booklet English Nature Science No. 11. Peterborough
Putwain, P.D. and Rae, P.A.S. (1998). Heathland restoration: a handbook of techniques British Gas: Southampton
Rodwell, J.S. (1992). British Plant Communities. Vol. 2 ‘Mires and heaths Cambridge University Press: Cambridge