Grazing of grasslands is essential because it maintains a sward composed of a wide variety of native grasses and other wildflowers. In the absence of grazing a few, taller-growing competitive species do well and smother the less vigorous species. As a result the diversity of grasses and other wildflowers is reduced. Eventually this process results in trees and scrub invading the grassland, which would thus turn into woodland. In upland situations, un-grazed grasslands may be first invaded by bracken, which also swamps out other species, before giving way to scrub and trees.

The main issues associated with the grassland areas of each of the Management Zones and detailed management objectives and proposals for actions to address these issues are outlined in Issues and Proposed Actions for Vegetation Management in the Management Zones of Land Held by the Malvern Hills Conservators (Alma 1999).

Management Actions for Grasslands:

• Pursue measures and increase awareness to facilitate increased grazing.

• Reintroduce and/or intensify grazing of open hill-top grasslands and where necessary on low lying commons.

• In the interim, the grasslands should be managed primarily by mowing, where practicable, or by strimming. Covering the growing turf with dense, cut stems should be avoided by removal of coarse debris. Mowing should focus on the slopes where grassland swards are becoming tall and rank.

• Machine-accessible areas should be mown rotationally in blocks in late summer, with the cuttings being removed from the site where practicable. Large contiguous areas should not be mown simultaneously, but should be mown in strips or blocks on rotation to preserve a mosaic of long, medium and short mown turf. This should be carried out with due regard to its impact on landscape values; where possible cutting should be carried out along the contours rather than in delineating vertical strips up and down slopes.

• Burning should generally be avoided, as it is damaging to invertebrate populations and can promote dominance by a few robust and competitive plant species. Where considered beneficial, burning should be carried out in very small blocks (<0.25 ha) on a rotation of several (i.e. 3-5) years.

• Clear encroaching bracken and some established bracken areas and some deciduous scrub and gorse from open grasslands (see below). It is recommended that this is done to the limits of closed canopy scrub that existed in 1990.

Reasons for Management of Bracken

Bracken has few natural controlling agents and is a very vigorous plant. If left unchecked it can take over large areas of a site to the detriment of most other plants. Once established, it produces a heavy shade in the growing season and toxifies the soil, which discourages other plant species from germinating. The dead fronds persist as ground cover throughout the year, decomposing slowly and building up progressively into a litter layer which can also suppress the ground flora. It may also be poisonous to livestock and is notoriously difficult to eliminate once it has taken hold.

Cutting or rolling/crushing several times during the growing season reduces the vigour of bracken, and if repeated for several years can bring it under control. However this is time consuming and labour intensive, and spraying is sometimes used as an alternative and should only be used with the agreement of English Nature on SSSIs. It is important that bracken is cut or treated during the growing season (see, for example, Lowday & Marrs 1992, Sutherland & Hill 1995); removal of dead fronds for fire hazard reduction is a much less effective way of reducing the vigour of bracken stands.

Bracken clearance can only be effective in the long term if grazing stock or continued treatment or cutting are subsequently used to suppress regrowth.

Bracken in upland situations can have an intrinsic wildlife value and attempts to remove bracken cover should avoid sites where it is important for its benefits to wildlife. For example, in the Malvern Hills several rare and scarce butterflies have larvae which develop on food-plants which grow beneath light bracken cover, including the rare high brown fritillary butterfly. It may also provide habitats for some uncommon nesting birds and is used by basking reptiles. The key factors in such situations are the identification of specific, important bracken sites and the maintenance of a thin cover, before it casts too dense a shade and before there is a deep build-up of dead bracken litter beneath.

There is a considerable contrast between light bracken and dense bracken cover. Dense bracken causes the most serious problem. Light bracken cover may be suitable for some butterflies, some shade requiring woodland plants and for adders. Where bracken is managed for the purpose of encouraging butterflies, cutting should occur so that the impact of cut swathes blends with the contour of the land and does not detract from landscape appearance.

In some areas of the hills, persistent stands of rose bay willow herb present a problem similar in some respects to bracken.

Management Actions for Bracken:

• Bracken should be cleared back from open grasslands, commencing at the encroaching edge. Initial clearance by mowing or crushing should be followed up by grazing or mowing so that a grass sward is established in order to prevent re-colonisation.

• Denser stands of bracken may require localised treatment, with follow-up grazing to break up litter and prevent re-colonisation. Bracken control should concentrate on actively growing stands and not be restricted to clearing dead fronds for reduction of fire hazard.

• Clearance of extensive bracken-dominated slopes is unlikely to be practical, especially in the absence of adequate grazing levels. Such areas should:
  • Be contained within prescribed limits;
  • Have small blocks (about 0.25-0.5 ha) mown or crushed (by machine or by hand) on rotation in spring and early summer, especially where follow-up access by grazing stock is possible;
  • Have wide (10-15 m) rides mown through annually; this should be carried out with due regard to its impact on landscape values; where possible cutting should be carried out along the contours rather than in delineating vertical strips up and down slopes.

• Burning should generally be avoided, as it is damaging to invertebrate populations and generally encourages dominance of the vegetation by bracken.