Action plan name
Mendip Heathland
Background and vision
A unique feature of the Mendip Hills is the range of grassland types and heathland that occur in close proximity. Rainfall is high on the Mendip Hills and this causes water-soluble ions to be lost from the surface as water drains away. In some places, this has allowed Heathland to develop directly on top of limestone. Such Limestone Heath supports acid loving plants alongside specialist limestone flora and is one of the special features of the Mendip Hills. While these characteristics are found across the Mendip Hills, this Biodiversity Action plan and its targets relate to the part of Mendip District only.
On the plateau, much of carboniferous limestone of the Mendip District is covered in a deposit of wind blown soil called loess. This loess contains very little calcium and soils that develop on it tend to be fairly acid unless lime is applied and in the past would have supported dry acid grassland tending to Heathland. Additionally, there is a large area of Heathland at Blackdown which is underlain by acidic rock called Portishead Beds. Other areas the Mendip plateau are underlain by the same geology, but these areas have mainly been planted up with conifers. Examples are Rowberrow, which lies adjacent to Blackdown Heathland, and Stockhill, which lies adjacent to the Mineries Heathland.
LBAP action in Mendip District is aimed at meeting landscape scale targets set out in the ‘Rebuilding Biodiversity/Nature’ methodology, concentrating efforts on ‘Strategic Nature Areas’ as shown in the Regional Spatial Strategy.
Rebuilding Biodiversity/Nature Map targets within Strategic Nature Areas will be met through a combination of measures:
• Increasing the average patch size of Priority Habitat Types
• Increasing the average patch size of Priority Habitat Type managed sympathetically
• Decreasing the distance between Priority Habitat Type patches
• Ensuring that Priority Habitat Type patches cover a range of altitudes and aspects to enable a wide range of conditions to be met
• Increasing the connectivity between Priority Habitat Type patches by sympathetic management of linear features as biodiversity corridors
Strategic Nature Areas for Heathland cover much of the plateau of the Mendips, however many of these contain only grassland and no existing Heathland. Unless underlain by particularly acidic geology, Heathland will only develop if favourable management persists for a very long time. Any actions taken towards restoration of Heathland will first of all result in seminatural neutral grassland, which over a long period of time might develop into acid grassland then Heathland.
Areas of Heathland reversion have been incorporated into the Forest Design Plans of Forestry Commission managed woodlands in the Mendip District within the scope of the UK Forestry Standard (UKFS) and UK Woodland Assurance Standard (UKWAS) guidelines.
Being a successional habitat, it can be argued that Heathland is one that can be well provided for within the transitional nature of coniferous rotations, as an alternative to trying to maintain permanent Heathland areas. Areas of Heathland within conifer plantations provide an ephemeral habitat for many Heathland specialists such as Long-eared Owl and Nightjar. These species would probably disappear from the Mendip District if the area reverted to permanent Heathland from conifer plantations. Liaison between partners will help decide the best balance between Heathland and conifers in these areas, bearing in mind the need to achieve rebuilding biodiversity/Nature Map targets and the best management regimes to achieve this, for example by grazing.
Plan species and habitats
• Nightjar
• Longeared Owl
• Brown Hare
• Adder
• Marsh Fritillary
• Tree Sparrow
• Dartford Warbler
• Striped Winged Grasshopper
• Flora of metal rich tips such as Spring Sandwort
• Lead Moss
• Habrodon perpusillus (moss)
• Rhytidium rugosum (moss)
• Cladonia Convoluta (lichen)
• Dry Acid Grassland and Heathland
• Lowland meadow
• Coastal and Floodplain grazing Marsh
Habitat status
Lowland Heathland is a UKBAP Priority Habitat.
Lowland Acid Grassland, Lowland Meadows and Calamarion (the special habitat found on lead contaminated land) are other UKBAP Priority Habitats likely to benefit from this HAP.
Calamarion is additionally an EU Habitats Directive Annexe 1 Habitat.
Blackdown is a Local Wildlife Site as is Stockhill Plantation on account of its remnant Heathland.
Several SSSIs on the Mendip Scarp support Heathland.
Specific impacts/threats
• Coniferous and broadleaved plantations - occupy most of the areas within Mendip District which are best able to be restored as Heathland.
• Current Leases on Forestry Commission managed land - currently disallow plantations to be replaced by other habitats such as heathland.
These plantations however, have developed into diverse habitats in their own right, supporting a wide range of species, including several SAP species. In addition to this, they have become important areas for public recreation, including interaction with wildlife, and of course contribute towards climate change mitigation by producing sustainable raw materials.
• Agricultural improvement – Lime application, ploughing and reseeding, fertiliser and slurry application
• Scrub invasion - following lack of grazing
• Climate change - could threaten this habitat
• High levels of aerial nitrogen deposition - could result in loss Heathland vegetation due to eutrophication
• Afforestation on areas of this habitat - both to commercial forestry and to new grant-aided woodland planting. Fortunately in Somerset the Forestry Commission currently has well trained staff who can recognise semi-natural habitats and avoid grant aiding planting on them and new commercial planting is subject to Environmental Impact Regulations. However, afforestation remains a potential threat.
Proposed Partners
Mendip District Council (MDC)
Mendip Area of Natural Beauty (MAONB)
National Trust (NT)
Somerset Wildlife Trust (SWT)
Private Landowners
Natural England (NE)
Private landowners
Farming and Wildlife Advisory Group (FWAG)
Forestry Commission (FC)
Current action
• Mendip Hills Living Landscapes Project
• SWT Reserve Management
• National Trust Reserve Management
• Environmental Stewardship and Wildlife Enhancement Scheme Funding
• Management on SSSIs to achieve favourable management status by 2010
• AONB work
Target description and target goals
1. To maintain existing extent and quality of Heathland
Goal: 210 ha by 2011
2. Restore existing areas of Heathland with dense scrub or bracken
Goal: 20 Ha by 2011
3. Initiate and carry out work likely to re-create Heathland by 2030 within SNAs
Goal: 100 ha by 2011
4. Initiate process of longer term Heathland restoration unlikely to meet rebuilding Biodiversity targets by 2030
Goal: 1200 ha by 2011
5. To achieve required match funding for Mendip Hills Living landscapes Projects (to match Tubney Trust funding)
Goal: £184 k by end of 2011
Key factors
• Revision of Forestry commission leases to enable restoration of Heathland on land currently under Coniferous and Broadleaved plantations. This may well be addressed in FC’s forthcoming Open Ground Policy. There is a need to find a way of enabling open ground within woodlands to be appropriately managed to maintain open ground habitats; this would often be through grazing.
• Availability of HLS funding to achieve habitat restoration goals.
• Successful Partnership working.
• It may be necessary to revise Strategic Natural Area boundaries to ensure that these reflect the most realistic areas for achieving Rebuilding biodiversity/Nature Map boundaries.
• The whole of Mendip District already has an aerial photo baseline Habitat Survey which will enable facilitate targeting and monitoring outcomes.
• Achieving match funding for Tubney Trust Grant Aid.
• The UKFS guidelines state that areas of important open ground habitat can be successfully restored by clearance of plantations. Forest Design Plans for Mendip District coniferous plantations should ensure the best balance for Heathland habitat and species and forestry.