the protection of the rock features." Collecting of geological specimens is not allowed. Heath The plants on both wet and dry upland heath have developed a requirement for acidic and nutrient-poor soil, which is at least partially affected by underlying layers of Sphagnum moss, or peat. Thus the prevalent mixture of low shrubs, heather and cottongrass will support a large number of animals and insects. Careful maintenance of dry heath requires just enough livestock grazing to keep down trees and shrubs, but minimum winter grazing to protect those same shrubs. Animal feed should not be placed on this habitat because its detritus and animal dung would enrich the soil. Where necessary, grazing should be temporarily withheld, to allow the vegetation to recover. Although as of 2020 local farmers have not used their grazing rights recently, the National Trust may reintroduce this heath maintenance method. Most wet heaths require little management, but if necessary a little light grazing may be used to prevent encroachment of trees and shrubs. Heavy grazing should be avoided on wet heath because it damages the peaty soil. Heather-burning should only take place with the agreement of English Nature, because burning can destroy adjacent woods, destroy some plants, destroy cover for certain nesting birds, encourage erosion, and encourage dominance of bracken and gorse. Cutting, if done without machinery, is a good alternative to burning, because it preserves the soil. Artificial drainage of wet heath is discouraged, because it would change the nature of the habitat. Woodland This is upland, semi-natural woodland. The clean air and high rainfall have made it a habitat for flora and fauna which is less commonly found in lowland woodland. However, beneficial previous and present management of this woodland has protected it from overgrazing, allowing plants and animals to proliferate. Where appropriate, woodland may be protected from livestock by fencing, it may be partially coppiced to let in light, or trees may be allowed to grow and die naturally. Invasive, not-native plants such as rhododendron should be removed. Wet woodland should be left alone where possible, allowing trees to grow and fall naturally. Any underplanted conifers should be removed. The mix of plants where the woodland and heath blend should be retained. Development and risk assessment For assessment, Natural England has divided the site into five units. Numbers one (), two () and four () are described as upland dwarf shrub heath, and