Upland heathlands are generally found above the upper edge of enclosed agricultural land at around 300 - 400 m in altitude. Some sites below 300 m may also display upland characteristics and are regarded and managed as such. Upland heath is characterised by the presence of dwarf shrubs, such as heather Calluna vulgaris and bilberry Vaccinium myrtillus. They tend to develop on nutrient poor acid soils which receive over 100 cm of precipitation per annum. They often form a mosaic with acid grasslands.
Dwarf shrub heath has a limited global distribution and is largely confined to the British Isles and the western seaboard of mainland Europe. Britain therefore holds a significant proportion of the world resource of this habitat.
Upland heathlands are also important for the populations of breeding birds which they support. These include species such as curlew, snipe and redshank, black grouse, ring ouzel and red grouse, as well as birds of prey such as merlin and hen harrier. Many upland sites contain nationally and internationally important populations of birds. Upland heathlands may also support a range of specialised invertebrates, such as the bumblebee Bombus monticola, a species which has suffered a dramatic decline in the region.
There is currently estimated to be between 2 and 3 million ha of upland heath in the UK, of which 270 000 ha is thought to be in England. The habitat has suffered considerable losses in recent times, with 27% of the heather moorland in England and Wales estimated to have been lost between 1947 and 1980. Much of this loss is attributed to agricultural land improvements, heavy grazing by sheep, and afforestation. It has been estimated that 440 000 ha of land in England and Wales is made up of grassland containing suppressed dwarf shrubs. There is likely to be further significant loss of heather moorland to acid grassland if current grazing levels and pressures continue.
The North East has extensive tracts of upland heath. There is at least 51 162 ha of upland heathland within the region which represents around 19% of the English resource. Much of this can be found in the North Pennines, the Northumberland National Park, and in the Tees Valley portion of the North York Moors. The most important tracts of upland heath have been designated as SSSIs. Some sites are also considered to be of international importance for their heathland habitats and/or bird populations and have accordingly been designated as SACs and Special Protection Areas (SPAs).
- Heavy grazing, especially by sheep, leads to the suppression of dwarf shrubs and ultimately to conversion to acid grassland. This can be exacerbated by a lack of shepherding which prevents stock utilizing the whole of the grazing land available to them. Inappropriate supplementary feeding practices can lead to localised over-grazing and nutrient enrichment.
- Lack of management can allow encroachment of scrub and trees and succession to woodland.
- Bracken invasion is a problem at several sites and can lead to a loss of dwarf shrubs.
- Difficulties in negotiating agreements with commoners are hampering take-up of agri-environment schemes on common land.
- Poorly managed heather burning can damage or eliminate lower plant communities and lead to a monoculture of heather at the expense of other plant species.
- Conversion to grassland through ploughing, reseeding, liming, and fertilization for agricultural purposes may take place, particularly at lower elevations on enclosed allotment land. Drainage and moorland gripping may reduce the interest of wet heaths. These factors have become less significant over the last ten years.
- Raptor populations are still subject to persecution.
- Quarries, windfarms, communication masts, access tracks and other planning developments can impact directly on the wildlife interest of upland heathlands.
- Localised damage and disturbance from other forms of land use in the uplands, such as recreation, may be a concern in some areas.
- Afforestation leads to the direct loss of dwarf-shrub habitat.
- The interaction of two or more of the factors listed above often greatly increase the impact on upland heathland vegetation. For example, poorly managed burning followed by heavy grazing will result in the loss of dwarf shrubs more rapidly than either factor in isolation.
- Areas of marginal land surrounding upland heath are an important habitat for many of the birds of open moorland and are under pressure from agricultural improvement.
Opportunities for protection and enhancement
- Agri-environment schemes such as Environmental Stewardship provide grants for the sympathetic management of upland heath and for the restoration of suppressed heather.
- Recent progress has been made on several North Pennines sites in negotiating agreements by commoners to permit entry into agri-environment schemes.
- At national and international level policy change to reduce overgrazing in the uplands, such as reform of the Common Agricultural Policy (CAP), would be of great benefit to upland heathlands.
- Restructuring of conifer blocks offers the opportunity to recreate or restore areas of heath. For example, on Wooler Common 160 ha of conifers are being removed and restored to heather moorland.
- Grouse moor management acts as an economic driver for habitat management in the uplands and has provided funds for works aimed at increasing heather cover.