Heathland habitat audit

For the purpose of this audit, heathland is defined as habitat characterised by the presence of heather Calluna vulgaris and gorse Ulex Spp. Heathlands usually occur on free-draining acid soils below 300m in altitude. Areas of good quality heathland consist of a shrub layer of varying height and structure, a scattering of trees and scrub, areas of bare ground, and occasional flushes and open water.

Only small fragments of heathland remain in Greater London. This resource has been much reduced in distribution and is of variable quality. However, heathland still represents a significant habitat in London, particularly because of its presence on Wimbledon Common and scattered patches on sites throughout the capital. There are about 80 hectares of heathland remaining in Greater London in total.

Lowland heathland is a scarce and declining habitat in Europe and is of international importance. The UK has approximately 20% of the global resource of this habitat, of which the largest proportion (55%) is found in England.

In Greater London many of the plant species associated with this habitat, such as dwarf gorse Ulex minor, petty whin Genista anglica and cross-leaved heath Erica tetralix, are locally rare and threatened. Some, such as cotton grass Eriophorum angustifolium, are confined to a single site.

Heathland has probably always been a relatively uncommon habitat in London. It is confined to the areas where sandy or gravely soil occurs and was reliant historically on grazing of livestock and clearance of invasive trees and shrubs to maintain the characteristically open nature of this habitat. Some areas of heathland arose as a result of turf-cutting which removed the fertile topsoil to expose areas of sand and gravel beneath.

There are some opportunities available to extend the existing heathland resource by utilising heathland restoration and re-creation methods in suitable areas adjacent to existing areas of habitat, or where heathland was formerly known to exist. The main constraints are the loss of formal recreation areas, the loss of acid grassland that may have its own special interest, or the loss of secondary woodland (often much-valued by the public) which has replaced the former area of heathland. There may also be the potential for the restoration of mineral workings (sand and gravel pits) to heathland. Re-instatement of grazing may be feasible on the more extensive heathland areas.