|IPA Factsheet - Salisbury Plain, Cranborne Chase and Pewsey Downs|
Site Description Salisbury Plain in central southern England is believed to be the largest surviving semi-natural dry grassland within the EU and is therefore the most important site for this habitat in the UK. Cranborne Chase derives from an ancient hunting forest, and includes remnants of enclosed medieval coppice, commonland wood pasture and 19th century hazel plantation. To the south, Cranborne Chase with its smooth rounded downs, steeply cut combes and dry valleys shows a typical chalk landscape. To the north, the topography of the Wiltshire Downs is more varied and broken, with shapely knolls and whaleback ridges. Both areas are fringed on the west by an impressive scarp, cresting above the adjoining clay vales. Traditional downland pasture is now largely confined to steeper slopes but large rectangular fields emphasise the chalkland's open character. The chalkland valleys of the Wylye, Nadder and Stour are mainly in permanent pasture, with many copses and hedgerows. In the northwest, the AONB's sandstone fringe of wooded ridges and valleys includes rich parklands such as Longleat and Stourhead.
Botanical Significance Salisbury Plain: Habitat interest. Juniperus communis formations on heaths or calcareous grasslands. Semi-natural dry grasslands and scrubland facies: on calcareous substrates (Festuco-Brometalia). It supports extensive examples of CG3 Bromus erectus grassland and the rare CG7 Festuca ovina – Hieracium pilosella – Thymus praecox grassland, and one of the largest examples of CG6 Avenula pubescens grassland. The site supports the largest UK population of the nationally scarce burnt orchid Orchis ustulata, together with significant populations of green-winged orchid Orchis morio and frog orchid Coeloglossum viride, both uncommon orchids associated with calcareous grassland.Salisbury Plain is the best remaining example in the UK of lowland juniper Juniperus communis scrub on chalk. The juniper is juxtaposed with extensive 6210 semi-natural dry grassland and chalk heath. Most of the scrub is of the southern mixed scrub type and is enriched by roses Rosa spp., wild privet Ligustrum vulgare, dogwood Cornus sanguinea, wayfaring tree Viburnum lantana and other species characteristic of the type. Cranborne Chase Epiphytic and other lichens, Ash/maple woodland, Coppice woodland, chalk downland flora. The ground flora is exceptionally rich in plants closely associated with ancient woodland. The Chase is one of the richest sites for lichens in southern England, with over 160 lichens recorded. Thirteen species are rare in Britain, including Pannaria conoplea, a lichen associated with ancient woodland in the oceanic climate of western Britain, Sticta sylvatica which grows on mossy tree trunks largely in the north and west, and Usnea articulata, a formerly widespread species which is extremely susceptible to sulphur dioxide pollution and now virtually confined to the south-west. Prescombe Down is one of three sites selected in the central part of the range for early gentian Gentianella anglica. It holds very significant populations of hundreds of thousands of plants in high-quality chalk grassland that has been sympathetically managed for many years.
General Habitat Description Salisbury Plain: Grassland and tall forb Cranborne Chase: Grassland, Woodland and forest, regularly cultivated agriculture
Conservation Issues Cotoneaster integrifolius has been known at Fontmell & Melbury Downs since 1991. - Inability to adapt to climate change due to past arable conversion causing habitat fragmentation and reducing extent of resource. - Lack of grazing on the scarp slopes leading to the development of coarse grassland and scrub encroachment. - Decrease in habitat quality due to application of artificial fertilizers, probably exacerbated by aerial nitrogen deposition. - The IPA core areas are distant from one another and some barriers are insurmountable – e.g. Salisbury city - The extent of the IPA is difficult to define due to neighboring areas of species-rich chalk grassland – e.g. Porton Down.