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Nature and Wildlife - Best Practice
Towards Best Practice in the sustainable management of sand dune habitats
Multiple-use management of the Ainsdale Dunes on the Sefton Coast
The Ainsdale dunes and foreshore including the Ainsdale Sand Dunes National Nature Reserve (NNR) and part of the Ainsdale and Birkdale Sandhills Local Nature Reserve (LNR) have long been recognised as an outstanding area of wildlife interest. Since the time of the 1915 Rothschild list, a series of designations has been attached to the area including Nature Conservation Review Grade 1* site, Geological Conservation Review site, NNR, LNR, Ramsar site, Special Protection Area (SPA) (the intertidal area), Site of Special Scientific Interest (SSSI) and, most recently, part of the Sefton Coast candidate Special Area of Conservation (cSAC). A high proportion of the area comprises EU fixed dune priority habitat. Key species include the Sand Lizard Lacerta agilis, the Natterjack Toad Bufo calamita and the liverwort Petalwort Petalophyllum ralfsii.
The area covers approximately 7km2 of the 22 km long Sefton Coast dune system. Some five million people live within one hours drive of the Sefton Coast, putting considerable pressure on this natural resource. Management of the NNR is undertaken by English Nature, the statutory wildlife agency for England, whilst that on the LNR is by Sefton Council, the local authority. This is co-ordinated across the whole Sefton Coast by the Sefton Coast Management Scheme. Both agencies have produced management plans for their sites.
The fixed dunes and associated species suffer from a number of factors threatening to reduce their nature conservation value. The spread of scrub and rank vegetation, in particular, leads to associated problems of soil development and the desiccation of slacks.
Scrub and growth of rank vegetation
Scrub invasion includes the establishment of tree and shrub species within the open dune landscape, particularly non-natives such as pine (predominantly Pinus nigra laricio), PoplarPopulus spp. and Sycamore Acer pseudoplatanus but also the native Sea Buckthorn Hippophae rhamnoides and birches Betula spp. This leads to the development of scrub woodland, a semi-natural habitat but one which results in a loss of valuable open dune habitat. In addition, low woody shrubs, such as Creeping Willow Salix repens, have grown tall and dense. Elsewhere an increase in rank grasses and herbs particularly brambles Rubus spp. has produced a dense undergrowth in areas not yet affected by scrub. These changes have led to a reduction of bare sand and short turf and therefore the high ground level temperature regimes which are a requirement of many dune species. Outbreaks of myxomatosis since the mid 1950s have significantly reduced rabbit numbers and have played a major role in these habitat changes.
Ainsdale beach is a popular tourist area and with large numbers of visitors to the beach, there are inevitably pressures put on habitats and species. The large number of visitors can lead to dune erosion and a loss of habitat quality. Associated activities such as litter, vandalism, fire and the collecting of rare species can cause considerable damage and take up staff time better spent on other nature management. In some circumstances, controlled or low trampling pressure can help to maintain short turf habitat and bare sand patches. Visitors come for a variety of reasons. Most come to the beach where they can park their car and make short forays into the dunes.Some come to walk the dunes, often for exercising a dog. Fewer come for quiet enjoyment, to experience the wild landscape and to observe the wildlife.
Aim of management
Management aims to conserve the range of open sand dune habitats and species for which the area was designated, whilst enabling appropriate public access and informing and educating those visitors (Gee, 1998; Sefton MBC, 1993).
Monitoring by fixed-point and aerial photography and casual observation has shown that important habitats and species would be lost without active intervention. Site managers have spent 30 years developing techniques to conserve the fixed dune habitats. These include scrub cutting and clearance, mowing, turf stripping, re-profiling and more recently, grazing with domestic animals (Houston, 1997).
Scrub cutting and clearance
Initially this work was carried out by site managers and volunteers using only hand tools. Priority sites were targeted but only small areas could be cleared at a relatively high cost. Cut stumps required herbicide treatment but this was not always succes sful and was not deemed environmentally sound. The need for larger scale operations and more sustainable techniques was clear. It was also found that rank ground vegetation was becoming a problem and needed special treatment. Mechanisation of scrub clearance by using bulldozers, excavators or tractors with specialised rakes and grabs enabled large areas to be cleared and this was often more successful than scrub cutting because the roots were also pulled out (Rooney, 1998). However such techniques are expensive, cause some damage to dune topography and are not as sustainable and green as site managers would wish. Monitoring studies have confirmed the value of scrub clearance as former dune habitats have returned, usually after a flush of ruderal plants (weeds) in the first few years. However where other techniques cannot be used, and prior to grazing an area, this is still an important technique.
Mowing was used on the NNR in the 1980s to control the height and density of Creeping Willow in dune slacks where it was rapidly overwhelming the short botanically diverse dune turf. Trials began in 1979 and the technique has graduall y been improved. Cut material has always been removed to avoid a build-up of nutrients and the development of thatch smothering the seedbank. In some areas a moss Calliergon cuspidatum, associated with Creeping Willow, has been raked out as it also smothers the underlying dune slack seedbank. Cuttings were hand-raked and removed off-site by tractor and trailer. Now elsewhere on the coast, forage-harvesters are used to cut and collect vegetation on grassland and heathlands. Cut material can be used to surface paths or be rotted down to a mulch for use elsewhere. Both flail and rotary mowers have been used and both have been successful. Flails tend to produce a cleaner cut, though if raking, because material is chopped up, it is more difficult to collect. Rotary chains have been found to be more successful than blades which tend to require more maintenance. Smaller tractors and mowers and lower ground pressure tyres cause less damage to slack topography and therefore micro-habitat. Following a visit to Dutch sites in 1987, the mowing of Creeping Willow was changed on the NNR from autumn to spring, as this has been shown to reduce its vigour more effectively. However this is not appropriate in wet slacks due to the presence of amphibians and damage caused to the soft turf.
Monitoring has shown an increased botanical diversity in mown slacks, but there are problems associated with mowing. It is not a truly sustainable activity across all areas that require management. Some areas are just not accessible. Mowing can also cause soil compaction and reduce micro-topography leading to greater uniformity of swards. Raking cut vegetation can be very labour intensive.
Turf-stripping and excavation
In the drought years of the mid 1970s many slacks in the NNR were scraped to provide breeding pools for the Natterjack Toad. It was found that the margins of these scrapes developed a diverse slack flora which has been monitored over the years. Tracked excavators are the best equipment to use and certainly wheeled vehicles should never be used in slacks. Small scrapes can even be hand-dug. Ho wever vegetation succession dictates that without further management these scrapes will eventually turn to scrub. Continual intervention will be necessary to maintain early stages of succession unless the grazing pressure is relatively intense. Such regular intervention may cause damage to other site features and difficult decisions may have to be made. The turf and spoil excavated should ideally be buried, otherwise an area of ruderals (weeds) will develop around the scrape. The burial should be capped by a minimum depth of one metre of pure sand. Similar results were gained from the re-profiling of over-deepened scrapes showing how resilient dune communities can be if provided with suitable conditions (Simpson, 1998).
Turf-stripping and excavation can certainly re-create early phases of dune succession and may be an important management technique for rare plants such as Petalwort. However some disturbance will be caused to the site with each action which in the long term could lead to a significant percentage of the site being modified. It is costly and not a green approach. Ideally in an actively accreting system, scrapes should not be necessary as natural processes should result in the creation of young embryo slacks.
For centuries rabbits had been an important influence on the ecology of the Sefton dunes. Following the outbreaks of myxomatosis in the mid-1950s the balance was lost and the dunes became overgrown with a loss in value for nature conservation. Domestic grazing was re-introd uced onto the Ainsdale dunes by English Nature in 1990. It was previously practised on the rearward dune areas along the coast until the late nineteenth century. Domestic grazing has proved to be the most successful and appropriate form of vegetation ma na gement. It has controlled target species such as Creeping Willow, there has been an increase in species diversity with a corresponding return to a low structural mosaic of vegetation with bare sand patches. Domestic grazing has encouraged a resurgence in the rabbit population and successfully maintained early successional stages in scrapes. Herdwick sheep from the English Lake District have proved to be a particularly effective and appropriate type of grazing stock with relatively low staff input and m ai ntenance costs, allowing staff to deal with other key projects (Simpson and Gee, 1997). Hebridean sheep and Aberdeen Angus and Hereford cattle have proved their value, but presently for resource reasons cannot be accommodated within the grazing regime. With increasing knowledge and understanding, adjustments are being made to the grazing regime to ensure the best possible results are achieved for wildlife. Such is the success of domestic grazing on the NNR that Sefton Council have approved a grazing trial on seven ha of the adjacent LNR. This is an open access public area and the establishment of a grazing project will require the support of local people and visitors alike. Public relations work and the provision of access points along desire lines is planned.
Blowouts create new sandy habitats within the fixed dunes including incipient slacks, especially important for annual plants, specialised invertebrates, Natterjack Toads and Sand Lizards. They are an important element of the dynamic processes within the dune system. However where recreation causes erosion, and particularly where property or infrastructure is threatened, dune restoration techniques are used. Dune stabilisation works have been necessary adjacent to the coastal road, near a holiday village and to prevent sand encroachment onto the railway line.
Three key species present in the Ainsdale hills area are protected by both European and national legislation. These are the Natterjack Toad, Sand Lizard and Petalwort. Ideally, management aims to conserve these species through broad scale habitat or process management. However to ensure their survival specific measures are taken or considered for each species.
A series of Natterjack Toad key pools are maintained as breeding pools. This involves some intensive management including the occasional reprofiling of scrapes to ensure open conditions with a deepened section to provide water in drought years. Split paling fencing is used to protect pools in areas with high public pressure and interpretation signs and wardening help to explain the importance of this species (Simpson, 1992).
Sand Lizards are most frequent in the transitional mobile/fixed dune habitat near the beach. Therefore there is the potential for disturbance from visitors. To reduce the risk, fencing is erected to protect sensitive sites and minor paths may be re-routed. Where vegetation conditions are becoming overly fixed, for example due to a temporary decline in rabbit numbers, small bare sand patches may be maintained (EAU, 1992).
Petalwort is a liverwort which favours conditions found in the early phases of dune slack succession. Grazing, light trampling and disturbance appears to assist the conservation of this species. Presently a management strategy is being developed to addr ess these issues.
Visitor management on the NNR and LNR is part of a wider zoning system used on the Sefton Coast as a whole. This identifies honeypot areas such as Ainsdale beach, closed or permit-only sanctuary areas such as the majority of the Ainsdale Sand Dunes NNR, together with a range of partial access and less intensively used sites in between such as the LNR. This has the advantage of encouraging the majority of people who come to the coast for the beach and associated facilities to be concentrated in a few areas where intensive management can take place to accommodate them. For example, facilities include laid-out car parks, boardwalks to the beach, fencing to protect dune habitats, trails, information boards, toilets and food and drink outlets. In this way the integrity of the dune system is maintained and pressure is taken off important habitats and species elsewhere on the coast. Ainsdale dunes are a good example of an access gradient from high, at Shore Road beach access point in the north, to low in the centre of the National Nature Reserve.
The quiet situation within the NNR provides a sanctuary for nature whilst allowing access by permit. The limited access also made the establishment of domestic grazing possible. With relatively low visitor numbers stock have not been troubled. Only small interpretation signs, together with articles in the local coastal magazine, guided walks and illustrated talks by the site manager have been required. Access by permit-only visitors, or views from the three main public permitted paths have generally been sufficient for those wishing to see the NNR fixed dunes. The LNR is open access to public visitors and includes several permitted paths as well as many informal footpaths particularly towards the beach. The waymarked paths encourage people to remain on them, leaving areas away from the path relatively undisturbed. In this way larger numbers of visitors can casually visit the dunes without undue disturbance to wildlife. However they are able to experience the wild nature of the site, the wildlife and to gain greater understanding of the need to conserve such areas. Nearer the beach access point, visitor access is more formal with beach car parking but with information signs and facilities as expected at a busy resort beach. This is supported by boardwalks and interpretation to reduce the impact to the dune and beach area and natural processes, whilst informing and enabling inquisitive visitors to discover more about the wildlife interest of the area.
The Sefton Coast Management Scheme has worked for twenty years to ensure the best possible management of the coast. Through its guidance, the footpath network and associated signage and interpretation system has been developed and standardised for the coast. It has also enabled greater integration of management actions and encouraged developments such as the proposal for domestic grazing on the LNR. It also assists with monitoring of dune condition across the whole coast and is working to develop management strategies for habitats and species across site boundaries.
Working towards Best Practice
The Ainsdale hills have seen more than thirty years of conservation management which have been gradually modified and improved. As a result of the Sefton Coast Management Scheme, management is now more fully co-ordinated along the coast. Strategies and plans inform site management and regular meetings are held for discussion and review.
The area needs to accommodate large numbers of visitors whilst effectively conserving the wildlife interest. In the quieter areas, domestic grazing has proved to be the ideal management tool. However scrub management and herbicide treatment is s till needed in the early years of such a project. In the seaward dunes most popular with visitors and other areas inappropriate for domestic grazing, a variety of techniques will be needed for vegetation management such as mowing, scrub management with h erbicide treatment and fencing of sensitive areas. Special management is required for a number of key species to ensure their survival and this has proved possible to achieve within annual work programmes. A wardening presence has proved to be important for visitor management and protection of rare species. In future it could be possible to manage sites better from a strategic viewpoint through, for example, the removal or variation of fencing boundaries and greater liaison between site staff across land ownership boundaries.
With careful management large numbers of visitors can be accommodated whilst conserving dune wildlife and spreading an important conservation message.
Produced by David Simpson and John Houston.
The work of Mike Gee, Site Manager Ainsdale Sand Dunes NNR, David McAleavy Head of Sefton Council Coast and Countryside, Peter Gahan Site Ranger Ainsdale Sandhills LNR and the support of the EC Life-Nature Fund is acknowledged in the preparation of this article.
Environmental Advisory Unit Ltd. (1992) Sand Lizard conservation strategy for the Merseyside coast. Unpublished report, English Nature, Peterborough.
Gee, M. (1998) Ainsdale Sand Dunes National Nature Reserve Management Plan 1998-2003. Unpublished report, English Nature report, Wigan.
Houston, J. (1997) Conservation Management Practice on British Dune Systems. British Wildlife, 8 (5), 297-307.
Rooney, P. (1998) A Thorny Problem. Enact, 6,(1), 12-13.
Sefton MBC (1993) Draft Ainsdale and Birkdale Sandhills Local Nature Reserve Management Plan (Parts 1 and 2). Unpublished report, Sefton MBC, Southport.
Simpson, D. (1992). Conservation of the natterjack toad (Bufo calamita) on the Sefton coast. Unpublished report, English Nature, Wigan.
Simpson, D. (1998). Bringing Back the Slacks. Enact, 6, (1), 9-11.
Simpson, D. and Gee, M. (1997). Setting up a grazing project. Enact,5, (4), 23-26.