Wiltshire Council HRA Report South Wiltshire Proposed Submission Core Strategy Appendix 3: N2K sites within South Wiltshire
APPENDIX 3: NATURA 2000 SITES WITHIN SOUTH WILTSHIRE
Site Name: Chilmark Quarries SAC
Description This complex of abandoned stone mines provides suitable hibernation conditions for a range of bat species and has a long history of usage by Greater Horseshoe Bats Rhinolophus ferrumequinum. It is regularly used by Barbastelle Barbastella barbastellus as a hibernation site as well as an important assemblage of other bat species, including Bechstein’s bat Myotis bechsteinii, for which this site has also been selected, indicating that conditions at this site are particularly favourable for the survival of these bat species.
Qualifying features Annex II species – primary reason for site selection:
Greater Horseshoe Bat (Rhinolophus ferrumequinum) Barbastelle (Barbastella barbastellus) Bechstein’s bat (Myotis bechsteinii)
Annex II species – present as a qualifying feature, not a primary reason for selection of this site:
Lesser Horseshoe Bat (Rhinolophus hipposideros)
(Source: www.jncc.gov.uk) Conservation objectives To maintain the designated interest features in favourable condition.
Component SSSIs and SSSI Name: Chilmark Quarries SSSI condition Favourable Unfavourable Unfavourable no Unfavourable Destroyed, part recovering change declining destroyed 0% 1.02% 98.98% 0% 0% Factors which maintain site • Roosts are sensitive to disturbance (internal as well as the entrances) which would need to be limited to acceptable levels. The integrity instillation of grilles at the entrance to the caves allows bat ingress/egress whilst reducing the human impact on the site. Activities of any kind within the site should be largely avoided during the general period of September – April each year to minimise the risk of disturbance to bats during the sensitive period of hibernation. Building or engineering works taking place within or around the area should be avoided, as should the use of vehicles or machinery that would be likely to produce noise, fumes or heat near roosting sites or access points that may disturb hibernating bats. • Maintenance of cool, stable temperatures (between 6 and 10oC). • Cave conditions should remain dark away from the entrances and ventilation stable.
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Wiltshire Council HRA Report South Wiltshire Proposed Submission Core Strategy Appendix 3: N2K sites within South Wiltshire
Site Name: Chilmark Quarries SAC
• Appropriate management of vegetation at roost entrances is required and there should be no artificial light shining on entrance or associated flight paths. The presence of tress can cause shading and damage by tree root growth can cause problems to structure. However vegetated cover around the entrance is desirable. • Bats require connectivity of habitat features for commuting and foraging. Active management of the habitats used by bats for these activities may be required. • The importance of linear habitat features off site for bat flight lines should be recognised. • Geological stability. May require inspection by geologist or mining engineer.
(Source: A statement of English Nature’s views about the management of Chilmark Quarries Site of Special Scientific Interest (SSSI), 2005) Vulnerabilities In recent decades the underground bat hibernacula have remained well protected from development and disturbance. The long-term safeguard of the hibernacula entails preventing the collapse of the underground voids and restricting unauthorised access. There is a costed ten-year management plan for Chilmark Quarries SSSI; however, disposal from the Ministry of Defence estate is currently in progress. The entrances at Fonthill Grottoes SSSI have been grilled under a management agreement, and access to the Grottoes is permitted under consultation with Natural England.
(Chilmark Quarries Natura 2000 Data Form, 2006)
HRA Appx 3 - N2K sites inside South Wiltshire.doc 2/17 NICHOLAS PEARSON ASSOCIATES July 2009
Wiltshire Council HRA Report South Wiltshire Proposed Submission Core Strategy Appendix 3: N2K sites within South Wiltshire
Site Name: Great Yews SAC
Description Great Yews represents yew Taxus baccata woods in the south-west of the habitat’s range. Although it is the smallest example of the habitat within the SAC series, it is important for the presence of about 300 old trees. It probably originated as yew wood following beech Fagus sylvatica or ash Fraxinus excelsior. It has some regeneration and so has the full structural and functional range expected of yew stands.
Qualifying features Annex I habitat – primary reason for site selection:
Taxus baccata yew woods of the British Isles
(Source: www.jncc.gov.uk) Conservation objectives To maintain the designated interest feature in favourable condition.
Component SSSIs and SSSI Name: Great Yews SSSI condition Favourable Unfavourable Unfavourable no Unfavourable Destroyed, part recovering change declining destroyed 100% 0% 0% 0% 0% Factors which maintain site Appropriate woodland management is required to maintain natural processes, a diverse woodland structure (re-growth), coppice and dead integrity trees), natural tree regeneration or stump re-growth, a diverse age structure, control invasive species e.g. Rhododendron ponticum or Himalayan balsam and support characteristic species (woodland flora).
(Source: A statement of English Nature’s views about the management of Great Yews Site of Special Scientific Interest (SSSI), 2004)) Vulnerabilities The woodland is currently considered to be in good condition. Little active management is carried out except small-scale recreational activity which at current levels does not have a significant impact on the interests. This management has been agreed on with the landowner through a site management statement. In the long-term, regeneration of the yew should be monitored and if necessary positive management carried out, which would require support through woodland grant schemes or management agreement.
(Source: Great Yews Natura 2000 Data Form, 2006)
• Deer browsing, if excessive can limit the capacity for natural regeneration via seedlings and saplings. • Lack of diversity of stand structure – many stands are in older age classes and because of the dense, dry and shady under-storey conditions below such stands, there is a lack of regeneration and little ground vegetation.
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Wiltshire Council HRA Report South Wiltshire Proposed Submission Core Strategy Appendix 3: N2K sites within South Wiltshire
Site Name: Great Yews SAC
• Air pollution - based on an assessment of the exceedence of relevant critical loads, air pollution is considered to be a potentially significant pressure to the structure and function of this habitat. However, it may well be the case that nitrogen loading is encouraging nitrophile species, such as bramble, to develop.
(Source: Joint Nature Conservation Committee. 2007. Second Report by the UK under Article 17 on the implementation of the Habitats Directive from January 2001 to December 2006. Peterborough: JNCC)
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Wiltshire Council HRA Report South Wiltshire Proposed Submission Core Strategy Appendix 3: N2K sites within South Wiltshire
Site Name: Prescombe Down SAC
Description 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. Prescombe Down is also designated for its large population of Marsh Fritillary butterflies.
Qualifying features Annex I habitats present as a qualifying feature, but not a primary reason for selection of this site:
• Semi-natural dry grasslands and scrubland facies: on calcareous substrates (Festuco-Brometalia)
Annex II species that are a primary reason for selection of this site:
• Early Gentian Gentianella anglica
Annex II species present as a qualifying feature, but not a primary reason for site selection 1 • Marsh Fritillary butterfly Euphydryas (Eurodryas, Hypodryas) aurinia
Conservation objectives To maintain the designated interest in favourable condition.
Component SSSIs and condition SSSI Name: Prescombe Down Favourable Unfavourable Unfavourable no Unfavourable Destroyed, part recovering change declining destroyed 71.52% 28.48% 0% 0% 0% Factors which maintain site Grassland integrity • Sward structure and composition provide a valuable indication of habitat quality. Cutting or grazing may be used to maintain these habitats, including control of scrub encroachment. • The presence of negative indicator species may indicate problems such as eutrophication, scrub invasion (insufficient control) or over or under grazing. • The application of pesticides, including herbicides, or any fertilizer would be damaging and should be avoided.
Marsh fritillary butterfly
HRA Appx 3 - N2K sites inside South Wiltshire.doc 5/17 NICHOLAS PEARSON ASSOCIATES July 2009
Wiltshire Council HRA Report South Wiltshire Proposed Submission Core Strategy Appendix 3: N2K sites within South Wiltshire
Site Name: Prescombe Down SAC
• Management of the site must maintain a mosaic of grassland and scrub habitats. The sward composition and structure needs to be maintained in a suitable condition. Particularly a significant population of devil’s bit scabious is required for the larvae to feed on and a high proportion of flowers in the summer for adult to feed on.
Early Gentian Inappropriate management, particularly reduction in grazing can lead to a loss or decline in this species.
(Source: SW RSS Habitat Regulations Assessment - Final Report – Appendix 3)
Vulnerabilities • Without management the chalk grassland rapidly becomes dominated by stands of rank grasses, such as Tor-grass. These grasses, together with the build up of dead plant matter, suppress less vigorous species and lower the diversity of the site. Eventually, the site will scrub over. • Insufficient and inappropriate grazing. The decline in the livestock industry in the UK threatens the long-term economic viability of the required extensive grazing by sheep and cattle. In the long-term, increased support through agri-environment schemes or management agreements may be required to maintain appropriate management. • Neighbouring landowners are diversifying, especially into shooting. Increased stocking of game birds could have an impact on the calcareous grassland, although negotiation is ongoing with the landowner to prevent this.
(Source: A statement of English Nature’s views about the management of Prescombe Down Site of Special Scientific Interest (SSSI), 2005 and Prescombe Down SPA Natura 2000 Data Form, 2006)
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Wiltshire Council HRA Report South Wiltshire Proposed Submission Core Strategy Appendix 3: N2K sites within South Wiltshire
Site Name: Salisbury Plain SAC
Description Salisbury Plain represents Juniperus communis formations near the southern edge of the habitat’s range on chalk in southern England, where it is particularly rare. This site is the best remaining example in the UK of lowland juniper scrub on chalk. The juniper is juxtaposed with extensive semi-natural dry grassland and chalk heath. In some cases the scrub has developed recently by invasion of open chalk grassland and contains few typical shrub species. However, 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.
Salisbury Plain 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. It supports extensive examples of CG3 Bromus erectus grassland, which is the most widespread and abundant calcareous grassland found in the UK. It also contains extensive areas of the rare CG7 Festuca ovina – Hieracium pilosella – Thymus praecox grassland, and one of the largest examples of CG6 Avenula pubescens grassland. The site also 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.
Marsh fritillary Euphydryas aurinia is present as a series of large sub-populations where the species breeds on dry calcareous grassland. The site extends the range of ecological variability included in the SAC series. Qualifying features Annex I habitats that are a primary reason for selection of this site:
• Juniperus communis formations on heaths or calcareous grasslands • Semi-natural dry grasslands and scrubland facies: on calcareous substrates (Festuco-Brometalia) • Semi-natural dry grasslands and scrubland facies: on calcareous substrates (Festuco-Brometalia) (important orchid sites)
Annex II species that are a primary reason for selection of this site: • Marsh Fritillary butterfly Euphydryas (Eurodryas, Hypodryas) aurinia
Conservation objectives Conservation objectives relating specifically to Porton Down:
To maintain, in favourable condition, the: • Semi-natural dry grasslands and scrubland facies on calcareous substrates (Festuco-Brometalia) – • Semi-natural dry grasslands and scrubland facies on calcareous substrates (Festuco-Brometalia) (important orchid sites) – • Juniperus communis formations on heaths or calcareous grasslands • habitats for the population of: - Marsh Fritillary (Euphydryas aurinia)
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Wiltshire Council HRA Report South Wiltshire Proposed Submission Core Strategy Appendix 3: N2K sites within South Wiltshire
Site Name: Salisbury Plain SAC
Conservation Objectives covering the Salisbury Plain SSSI have also been produced by Natural England, as follows:
To maintain, in favourable condition, the Lowland Calcareous Grassland, with particular reference to:
• Juniper; • Tuberous Thistle, a vascular plant species of lightly managed grasslands; • Cerastium pumilum, Dianthus deltoides, vascular plant species of disturbed/heavily managed grasslands, crumbly turf, path edges, etc. • Minuartia hybrida, vascular plant species of ruderal areas (Suite 9); • Vascular plant assemblage: Meadow Clary-Salvia pratensis (CG2-CG6), Dwarf sedge-Carex humilis (CG1-CG3), Slender Bedstraw- Galium pumilum (CG2-3, CG5), Early Gentian-Gentianella anglica (CG2-3), Burnt Orchid-Orchis ustulata (CG2-3), Field Fleawort- Tephroseris integrifolia (CG2-CG5), Bastard Toadflax-Thesium humifusum (CG2-3, CG5); • Non-vascular plant assemblage, including bryophyte species of disturbed open lowland calcareous grassland; • Non-vascular plant assemblage, including bryophyte species of hedgerows and wayside trees; • Aggregations of breeding bird species, namely Stone Curlew, Quail and Hobby; • Assemblage of breeding birds; • Hen harrier; • Individually notified invertebrates: Fairy shrimp - Chirocephalus diaphanus, Adonis blue-Polyommatus bellargus, Duke of Burgundy- Hamearis lucina, Brown hairstreak-Thecla betulae, Grayling-Hipparchia agestis, Narrow-bordered bee hawk-moth- Hemaris tityus, Nomada armata, Bombus humilis, Bombus sylvarum, Bombylius minor; • Marsh Fritillary; • Habitat-associated invertebrate assemblages: F111 sand & chalk (F11 unshaded early successional mosaic); • Habitat-associated invertebrate assemblages: F112 open short sward (F11 unshaded early successional mosaic). Component SSSIs and condition SSSI Name Favourable Unfavourable Unfavourable no Unfavourable Destroyed, part recovering change declining destroyed Porton Down 18.24% 61.12% 20.64% 0% 0% Salisbury Plain 14.34% 85.66% 0% 0% 0% Factors which maintain site Grassland integrity • Sward structure and composition provide a valuab le indication of habita t quality. Cutting or grazing may be used to mai ntain these habitats, including control of scrub encroachment. • The presence of negative indicator species may indicate problems such as eutrophication, scrub invasion (insufficient control) or over grazing (eg rabbits).
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Wiltshire Council HRA Report South Wiltshire Proposed Submission Core Strategy Appendix 3: N2K sites within South Wiltshire
Site Name: Salisbury Plain SAC
Juniper • Juniper scrub is a transitional stage that will develop into woodland if unmanaged. To retail the open, often flower rich character of juniper scrubland, it may be necessary to actively prevent other tree, shrub and invasive plant species from dominating the juniper through the use of carefully controlled grazing or cutting.
Marsh Fritillary butterfly • Management of the site must maintain a mosaic of grassland and scrub habitats. The sward composition and structure needs to be maintained in a suitable condition. Particularly a significant population of devil’s bit scabious is required for the larvae to feed on and a high proportion of flowers in the summer for adult to feed on.
Vulnerabilities This site comprises three landholdings: a military training area, a military research area and a National Nature Reserve. The interests of all three sites require low intensity grazing which on the military areas has occurred as a by-product of military use over many years and on the NNR has been maintained through traditional farm management. Lack of management is a problem in some places on the training area, and the decline in the UK livestock industry has implications for all three areas, such that future grazing management may require increased financial support. Changes in military use, particularly use of increased numbers of vehicles and construction of roads and tracks to accommodate those vehicles have the potential to damage the qualifying interests, but are subject to prior assessment and are being strategically addressed through an integrated land management plan. The land that is subject to purely agricultural use is managed sympathetically through a National Nature Reserve management plan.
(Source: Salisbury Plain SAC Natura 2000 Data Form, 2006 )
HRA Appx 3 - N2K sites inside South Wiltshire.doc 9/17 NICHOLAS PEARSON ASSOCIATES July 2009
Wiltshire Council HRA Report South Wiltshire Proposed Submission Core Strategy Appendix 3: N2K sites within South Wiltshire
Site Name: River Avon SAC
Description The Avon in southern England is a large, lowland river system that includes sections running through chalk and clay, with transitions between the two. Five aquatic Ranunculus species occur in the river system, but stream water-crowfoot Ranunculus penicillatus ssp. pseudofluitans and river water-crowfoot R. fluitans are the main dominants. Some winterbourne reaches, where R. peltatus is the dominant water-crowfoot species, are included in the SAC.
There is an extensive population of Desmoulin’s Whorl Snail Vertigo moulinsiana along about 20 km of the margins and associated wetlands of the Rivers Avon, Bourne and Wylye. This is one of two sites representing the species in the south-western part of its range, in chalk stream habitat. It occurs here in a separate catchment from the Kennet and Lambourn, within an environment more heavily dominated by arable agriculture.
The River Avon has a mosaic of aquatic habitats that support a diverse fish community. The Avon represents Sea Lamprey Petromyzon marinus in a high-quality river in the southern part of its range. There are excellent examples of the features that the species needs for survival, including extensive areas of sand and gravel in the middle to lower reaches of the river where sea lampreys are known to spawn. A healthy, stable population of Brook Lamprey Lampetra planeri also occurs in the main river and in a number of tributaries and this can be attributed to its clean beds of gravel for spawning and extensive areas of fine silt for juveniles to burrow into. The Avon also supports Atlantic Salmon Salmo salar and the populations here are typical of a high quality chalk stream unaffected by the introduction of genetic stock of non-native origin. The Avon has an excellent mosaic of aquatic habitats, which include extensive areas of gravels essential for spawning and growth of juvenile fry. Lastly, the Avon also represents Bullhead Cottus gobio in a calcareous, relatively unmodified river in the southern part of its range in England. The bullhead is an important component of this community, particularly in the tributaries.
Qualifying features Annex I habitat – primary reason for site selection:
• Water courses to plain to montane levels with Ranunculion fluitantis and Callitricho-Batrachion vegetation
Annex II species that are a primary reason for selection of this site:
• Desmoulin’s whorl snail (Vertigo moulinsiana) • Atlantic Salmon (Salmo salar) • Bullhead (Cottus gobio) • Sea lamprey (Petromyzon marinus) • Brook lamprey (Lampetra planeri)
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Wiltshire Council HRA Report South Wiltshire Proposed Submission Core Strategy Appendix 3: N2K sites within South Wiltshire
Site Name: River Avon SAC
(Source: www.jncc.gov.uk) Conservation objectives The general conservation objective for the River Avon cSAC, subject to natural change, is to maintain or restore in favourable condition:
The river habitat as characterised by: • Submerged or floating formations of Ranunculus and associated Callitricho-Batrachion vegetation
The river as habitat for populations of: • Atlantic salmon (Salmo salar) • Bullhead (Cottus gobio) • Brook lamprey (Lampetra planeri) • Sea lamprey (Petromyzon marinus)
The river and adjoining land as habitat for populations of: • Desmoulin’s whorl snail (Vertigo moulinsiana).
Component SSSIs and condition SSSI Name: River Avon System Favourable Unfavourable Unfavourable no Unfavourable Destroyed, part recovering change declining destroyed 3.73% 8.05% 83.72% 4.5% 0% Factors which maintain site Watercourse (Ranunculus) habitat integrity • The river’s natural structure and form should be maintained to support a natural flow regime. This includes the avoidance of the constriction of the river block age of its floodplain and the maintenance of natural erosion and sedimentation processes. • Riparian areas and the wider catchment need to be managed sensitively to avoid excessive run-off of soil particles and nutrients into the river. • The structure and composition of bankside and aquatic vegetation should be maintained. • The increased growth of epiphytic algae and planktonic algae can lead to excessive shading of plants, reduced seed germination, enhanced capture of silt.
Annex II primary species – Desmoulin’s whorl snail • Desmoulin’s whorl snail are sensitive to the structure and composition of marginal vegetation of rivers, structure and composition of tall fen and swamp vegetation, the water table and water quality. The site should therefore be managed to ensure these factors stay within
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Wiltshire Council HRA Report South Wiltshire Proposed Submission Core Strategy Appendix 3: N2K sites within South Wiltshire
Site Name: River Avon SAC
acceptable levels • Although some flooding is permissible the site should not be deeply flooded in summer months. • The snails may be vulnerable to direct damage, habitat change due to adjacent Newbury bypass, lowering of water table, water pollution and shading due to encroachment of larger plan species.
Annex II primary species - fish • The river’s natural structure and form should be maintained to support a natural flow regime that will help ensure the provision of resting pools for fish, conserve the quality of the river bed as fish spawning habitat, and avoid the creation of artificial barriers to the passage of migratory fish and other animals such as Otter. • Any exploitation of fish populations or other native animals or plants should be at a sustainable level, without manipulation of the river’s natural capacity to support them or augmentation of excessive stocking.
(Source: SW RSS Habitat Regulations Assessment - Final Report – Appendix 3) Vulnerabilities Watercourse (Ranunculus) habitat • Uncharacteristically low / high flow rates and velocities; • Elevated nutrient levels, high levels of suspended solids and elevated trace elements • Channel modification e.g. dredging, straightening (a varied river form provides opportunities for growth of different Ranunculus community species) • Elevated levels of siltation and suspended solids • Aquatic and riparian non-native species (effects can be both direct e.g. through increased competition and indirect as a result of increased shading, siltation) • Flocks of unmated swans and Signal Crayfish (can lead to over-grazing of new shoots)
Anne x II primary species – Desmoulin’s whorl snail • Vulnerable to effects siltation, elevated nutrient levels and invasion by non-native species might have on riparian vegetation communities on which they depend; • The snails may be directly vulnerable to organic pollution, particularly during periods of high flows when they can be immersed or transported. • Vulnerable to effects of herbicides and pesticides if used inappropriately near watercourse. • Drainage of wetland areas believed to be key threat to species. • Cannot tolerate regular cutting of riparian vegetation e.g. tidying of riverside footpaths, especially where there is no history of this form of management. • Lowering of groundwater levels. The critical minimum summer water level threshold, where the snail occurs but only at very low
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Wiltshire Council HRA Report South Wiltshire Proposed Submission Core Strategy Appendix 3: N2K sites within South Wiltshire
Site Name: River Avon SAC
abundance, is estimated to be 0.5 m below surface ground level. Equally, conditions should not be too wet such that aquatic plants e.g. Rorippa become dominant (some leaf litter is needed for over-wintering and laying eggs on).
Annex II primary species - fish • Eutrophication acts in a similar way to some other forms of pollution: the abundant algae and bacteria resulting from increased nutrients smother both the spawning gravels (preventing spawning or killing eggs) and the nursery silts, creating anoxic conditions there. • Siltation - fine silt can smother eggs, choke fish and disrupt feeding behaviour. For example, silt deposition over hard, coarse substrate reduces the available habitat that is necessary to bullhead for reproduction and shelter. • Larvae can survive almost anoxic conditions in their burrows for only a few hours after which they die. • Water quality - sea lamprey is known to be sensitive to pollution, and although few data are available, it has disappeared from rivers that have become polluted - assumed water quality B or better is required. Salmon require very good water quality, typical of that found in upland streams and spring-fed chalk (water quality classes A and B only). Susceptible to point-source pollution e.g. outfalls from WTW. • Life cycle is broken if there are any physical barriers to migration within the river e.g. weirs / waterfalls. Apart from actual barriers, any significant alteration or management of channels that removes too much cover or nursery gravels / silts creates long stretches of very fast flow (> 2 m s-1) must be avoided all along the migration route. Vertical structures of 18–20 cm in height found to be impassable to bullhead - populations upstream of such structures vulnerable to population fragmentation, isolation and ultimately extinction • Both water abstraction and land drainage can have negative effects on lamprey populations, leading to unstable habitats with variable levels of water. Summer flows must be sufficient to maintain adequate depth and velocity in juvenille rearing areas. Upstream migration also requires and is triggered by high flow. Low flows may result in elevated water temperatures and low dissolved oxygen during summer periods, causing salmon kills (Brooker et al. 1977), especially among the 0+ cohort (Cowx et al. 1984). • Complete removal of bankside vegetation can be detrimental as results in over-warming and loss of invertebrate food source for juvenilles.
(Sourc e: Wheeldon J (2003) The River Avon cSAC Conservation Strategy. English Nature, Peterborough.)
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Wiltshire Council HRA Report South Wiltshire Proposed Submission Core Strategy Appendix 3: N2K sites within South Wiltshire
Site Name: Porton Down SPA
Description Porton Down is situated on the Hampshire-Wiltshire border in the Test Valley and Salisbury districts of southern England. It consists of an extensive area of chalk grassland with scrub and woodland, and is one of the largest uninterrupted tracts of semi-natural chalk grassland in the UK. It is important for downland breeding birds and supports important numbers of Stone Curlew Burhinus oedicnemus.
Qualifying features The site supports the following species listed on Annex 1 of the Directive:
• Stone Curlew Burhinus oedicnemus during the breeding season (20 pairs representing at least 10.5% of the breeding population in Great Britain (Count mean (1995-99))
(Source: www.jncc.gov.uk) Conservation objectives To maintain, in favourable condition, the habitats for the populations of Stone Curlew of European importance, with particular reference to: • chalk grassland
Component SSSIs and condition SSSI Name: Porton Down Favourable Unfavourable Unfavourable no Unfavourable Destroyed, part recovering change declining destroyed 18.24% 61.12% 20.64% 0% 0% Factors which maintain site • Stone curlew rely on the availability of abundant pre species, therefore the management of the site should ensure that levels of these stay integrity within acceptable parameters. • The structure and composition of vegetation is important to provide suitable habitat for nesting, feeding and roosting. Traditionally, management is achieved by grazing and in the case of Porton Down by an excessive rabbit population, which should generally aim to keep a relatively open sward without causing excessive poaching. • Maintenance of mosaic of open stony ground with sparse vegetation and bare soil and short to medium height vegetation. This type of habitat provides suitable breeding sites for Stone Curlew as well as foraging habitat for invertebrate prey.
(Source: A statement of English Nature’s views about the management of Porton Down Site of Special Scientific Interest (SSSI), 2005) Vulnerabilities • Without management the chalk grassland on which the stone curlew depends at this site rapidly becomes dominated by stands of rank grasses, such as Tor-grass. These grasses, together with the build up of dead plant matter, suppress less vigorous species and lower the diversity of the site. Eventually, the site will scrub over. During the Salisbury Plain LIFE Natura Project a significant proportion of scrub was managed and now an ongoing scrub management programme continues, albeit at a lower level, to prevent significant loss of
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Wiltshire Council HRA Report South Wiltshire Proposed Submission Core Strategy Appendix 3: N2K sites within South Wiltshire
Site Name: Porton Down SPA
grassland to scrub. • Inappropriate grazing e.g. disturbance to Stone curlew when breeding needs to be avoided. • Disturbance - The site forms the ranges of the Defence Science and Technology Laboratory which is an agency of the Ministry of Defence, and military training activities take place. On the whole, the existing land use is compatible with maintaining the SPA interest, provided this is kept to an acceptable level. Management and operational issues continue to be dealt with through a working Integrated Land Management Plan and a generic consent which is periodically reviewed. Consent is issued by Natural England.
(Source: A statement of English Nature’s views about the management of Porton Down Site of Special Scientific Interest (SSSI), 2005 and Porton Down SPA Natura 2000 Data Form, 2006 )
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Wiltshire Council HRA Report South Wiltshire Proposed Submission Core Strategy Appendix 3: N2K sites within South Wiltshire
Site Name: Salisbury Plain SPA
Description The largest remaining area of chalk grassland in north-west Europe, Salisbury Plain is located in central southern England as a plateau of Upper and Middle Chalk to the north of Salisbury. Much of the area is used for military training, which has prevented the conversion of the ancient grassland to arable farming that has been so prevalent elsewhere in England. Rare plants include Tuberous Thistle Cirsium tuberosum and Meadow Clary Salvia pratensis. As well as the suite of grasses and herbs characteristic of open chalk grassland, Salisbury Plain supports important scrub communities with a wide variety of native shrubs, though these are small in extent compared with open grasslands. There are some important stands of Juniper Juniperus communis, while Hawthorn Crataegus monogyna, Buckthorn Rhamnus cathartica, Yew Taxus baccata and Wayfaring-tree Viburnum lantana are some of the shrubs present. There are also important assemblages of invertebrates (especially butterflies and moths, flies and bees) associated with both the ancient grassland and the successional scrub communities. Breeding Stone Curlew Burhinus oedicnemus and other birds are dependent upon the extensive areas of short grassland, and wintering birds forage over the grasslands and scrub. Raptors overwinter, feeding on small birds and mammals.
Qualifying features The site supports the following species listed on Annex 1 of the Directive:
During the breeding season;
• Stone Curlew Burhinus oedicnemus, 22 pairs representing at least 11.6% of the breeding population in Great Britain (Count as at 1998)
Over winter;
• Hen Harrier Circus cyaneus, 14 individuals representing at least 1.9% of the wintering population in Great Britain (RSPB 1996/7) Conservation objectives See details under Salisbury Plain SAC above. Component SSSIs and condition SSSI Name: Salisbury Plain SPA Favourable Unfavourable Unfavourable no Unfavourable Destroyed, part recovering change declining destroyed 14.34% 85.66% 0% 0% 0% Factors which maintain site SPA Annex I birds integrity • All species are vulnerable to disturbance and predation. The site must therefore be managed to keep these factors within acceptable parameters. • It is important that habitats found on this site support areas for these birds that are suitable for nesting and feeding.
HRA Appx 3 - N2K sites inside South Wiltshire.doc 16/17 NICHOLAS PEARSON ASSOCIATES July 2009
Wiltshire Council HRA Report South Wiltshire Proposed Submission Core Strategy Appendix 3: N2K sites within South Wiltshire
Site Name: Salisbury Plain SPA
Stone Curlew • Stone curlew rely on the availability of abundant pre species, therefore the management of the site should ensure that levels of these stay within acceptable parameters. • The structure and composition of vegetation is important to provide suitable habitat for nesting, feeding and roosting. The site should therefore be managed to provide the mosaic of open stony ground with sparse vegetation and bare soil and short to medium height vegetation. • Stone Curlew nest in short-sward grassland over thin, stony, free draining soils.
Hen Harriers • Maintain records of signs of human disturbance and limit disturbance affecting use of roost site by birds.
(Source: SW RSS Habitat Regulations Assessment - Final Report – Appendix 3) Vulnerabilities Salisbury Plain is owned by the Ministry of Defence and used intensively for military training. The grassland is robust and when dry is able to sustain considerable training pressure. Other land uses include agriculture, forestry and recreation. Military training requirements constrain ideal conservation management (including grazing and scrub management) and have led to the establishment of extensive plantations which, over time, may pose a threat to the open grassland landscape and its ecology. An additional threat is stone road construction: this has replaced rutted tracks with engineered stone roads over many kilometres. Any further road construction or development will be subject to stringent Environmental Assessments. The military training requirements, conservation management requirements and other land use issues have been brought together in an Integrated Land Management Plan (ILMP). This seeks to optimise military training whilst sustaining and enhancing nature conservation and other heritage interests. English Nature has been instrumental in the development of the Plan (presently in preparation), and will be closely involved in its usage, monitoring and refinement. The ILMP will address many issues including sustainability of military activities and management such as more extensive grazing, scrub management and removal of plantations not essential for military training. To achieve the objectives of the ILMP further sources of funding are likely to be required in the future.
(Source Salisbury Plain SPA Natura 2000 Data Form, 2006 )
HRA Appx 3 - N2K sites inside South Wiltshire.doc 17/17 NICHOLAS PEARSON ASSOCIATES July 2009