|IPA Factsheet - Dornoch Firth and Morrich More|
Site Description The estuary is fed by the Kyle of Sutherland and is virtually unaffected by industrial development. There is a complete transition from riverine to fully marine conditions and associated communities. Inland, and in sheltered bays, sediments are generally muddy. Gravelly patches occur in the central section of the Firth. Wide sandy beaches dominate the large bays at the mouth of the Firth, and areas of saltmarsh occur around the shores. Sublittoral sediments are predominantly medium sands with a low organic content. The site contains extensive areas of inter-tidal sand/mud flats, saltmarsh and sand dunes. The flats extend in a wide belt along the northern and southern shores and are characteristic of a range of environmental conditions. There is a continuous gradient in the physical structure of the flats, from medium-sand beaches on the open coast to stable, fine-sediment mudflats and muddy sands further inland. This results in a high diversity of animal and plant communities supporting polychaetes, oligochaetes, amphipods, gastropods and bivalves.
Botanical Significance Dornoch Firth and Morrich More represent Atlantic salt meadows habitat type in the northern part of its UK range. The site supports a wide variety of community types, with the characteristic zonation from pioneer to upper marsh vegetation. At Morrich More the saltmarshes lie adjacent to sand dunes and there are important transitions between these habitats There are well-marked lyme-grass Leymus arenarius-dominated areas of embryonic shifting dunes fronting the prograding sections of this site. The process of continued progradation is central to the conservation of this habitat type at this site, which has the largest, most complete area of sand dune in the UK, in part owing to the exceptionally high rate of progradation. The large dune system at this site is physically diverse, with areas of active accretion, areas of marine erosion and areas of internal instability. There are well-formed parabolic dunes in one area. All of these formations provide opportunities for shifting dunes along the shoreline with Ammophila arenaria to develop. As a result this habitat type is relatively extensive within the site. The vegetation is representative of northern mobile dune vegetation, with lyme-grass Leymus arenarius prominent in some stands. The site is largely undisturbed, resulting in a natural habitat structure. The fixed dune system with herbaceous vegetation consists of a low dune plain which is still developing in its outer part. The dune system consists of a series of ridges with heath and juniper scrub on the older ridges which grade into the fixed dune vegetation of maritime grassland in the mid and outer parts. The dune system consists of a series of ridges with heath and juniper scrub on the older ridges which grade into the fixed dune vegetation of maritime grassland in the mid and outer parts. The heathland at Cuthill and Skibo Links supports extensive and unusual lichen-rich lawns, where several rare lichens are present, including malachite-green felt lichen Peltigera malacea. The dune vegetation has developed on a coastline that has been generally rising relative to sea level in the 7,000 years since the last glaciation. A combination of leaching, stabilisation and the decreased influence of salt water has produced a sequence of dry, stable dune ridges, interspersed with wet dune hollows. There is a large area of decalcified fixed dunes with Empetrum nigrum vegetation on this site, occurring in a complicated mosaic of acidic fixed dune vegetation types, principally Atlantic decalcified fixed dunes (Calluno-Ulicetea). This is the most important acidic dune site in Scotland because of its size and the exceptional diversity of habitats within it. Despite some localised industrial development, structure and function are well-conserved at this site and accretion is continuing. The sequence of development of the dunes has resulted in the formation of extensive humid slack communities of an acidic character which lie as parallel hollows between the dune ridges and form part of a complex mosaic of dune habitats. At low tide, large exposed mudflats along the northern and southern shores reveal extensive eelgrass beds, with populations of both narrow-leaved eelgrass Zostera marina and dwarf eelgrass Zostera noltei. Bordering the mudflats, much of the land is very low lying, and supports extensive areas of saltmarsh and meandering tidal creeks. Saltmarsh is present near Dornoch, Ardjachie, Edderton and Poll na Caorach. Saltmarsh species such as glasswort Salicornia sp. and saltmarsh-grass Puccinellia maritima are found towards the seaward edge. Dornoch Firth and Morrich More has the most extensive area of Salicornia spp. saltmarsh in the UK. Further inland, the saltmarshes grade into extensive beds of pink thrift Armeria maritime, intermixed with sea arrowgrass Triglochin maritimum and sea plantain Plantago maritima. Sand dune vegetation at different stages of stabilisation is found in a number of locations. Sand colonised by marram grass Ammophila arenaria is constantly shifting its distribution particularly at Dornoch Point, whilst other exposed dune habitat locations are actively eroding through wave action. Large tracts of undulating stabilised dune ridges are found south of Dornoch. Where the dune vegetation is even more stable, acidic dune grasslands and coastal heathland form a mosaic of rare vegetation types. This habitat is very rare in the UK and Europe. The dune heath is dominated by ling Calluna vulgaris and bell heather Erica cinerea, with stands of burnet rose Rosa spinosissima, and dense mature stands of gorse Ulex spp. Flowering plants are typically few but include common dog-violet Viola riviniana, bird’s foot trefoil Lotus corniculatus, lady’s bedstraw Galium verum and wild thyme Thymus polytrichus. Lichen-rich dunes are relatively uncommon in relation to the area of dune habitat present within the UK. However, lichen-rich acid dunes are present in the north-east of Scotland in particular. Lichen-rich lawns flourish on shingle and gravel beds on exposed dune ridges and basins. These lawns support rare and unusual lichens including malachite-green felt lichen Peltigera malacea. However the site has been selected mainly for its assemblage rather than the presence of particular rare species. The heathland at Morrich More is the most important site in the UK for juniper Juniperus spp. stands on dune. Stands of juniper cover approximately 10 ha, with scattered individuals over a larger area. The juniper is extremely well-developed on the dry ridges and transitions to dune slacks. The best stands occur in grasslands in the southern sector, but prostrate individuals also extend into wet heath and slack habitats within the site. Morrich More and Loch Eye support seven species of stonewort: Chara aspera, C. contraria, C hispida, C. virgata, C vulgaris and Tolypella glomerata at Morrich More and C. aspera, C. contraria, C. virgata and Nitella flexilis agg. at Loch Eye (Stewart 2004). The varied coastal habitats support a range of nationally scarce vascular plants. Dwarf eelgrass Z. noltei and narrow-leaved eelgrass Z. marina thrive on intertidal mud and sand flats where physical disturbance is minimal. Baltic rush Juncus balticus and seaside centaury Centaurium littorale grow in the transitional zone between upper saltmarsh and damp dune grassland. Eyebright Euphrasia foulaensis is growing close to its southern limit in Britain on the east Coast. Other nationally scarce species include variegated horsetail Equisetum variegatum and slender-leaved pondweed Potamogeton filiformis, Pyramidal bugle Ajuga pyramidalis grows only in a very small area of the dune heathland at Skibo.
General Habitat Description Dornoch Firth is located on the east coast between Dornoch (Sutherland) and Tain (Ross-shire). The site is noted for its nationally important intertidal and coastal habitats, its populations of scarce plants and its populations of non-breeding bar-tailed godwit, whooper swan and wigeon. The fixed sand dune habitat at Dornoch, part of which falls within this site, supports a significant proportion of the largest small blue butterfly colony in Caithness and Sutherland. It is dependent on kidney vetch. Morrich More is a large dune system on the south side of the Dornoch Firth, to the east of Tain. It contains a number of shallow lochs and swampy pools that are strongly calcareous. Loch Eye occurs in a shallow basin a few miles to the south. The site is an RAF bombing range and depressions created by bombs are also of interest for stoneworts. The site contains extensive saltmarsh habitats with numerous creeks and brackish pools especially on the north side of Inver Bay. The saltmarsh grades into an equally extensive range of dune, heath and coastal grassland habitats with abundant juniper scrub in places. The variety and scale of the coastal landforms at Morrich More SSSI is outstanding. These landforms include mobile parabolic and foredunes, stabilised grey dunes, salt marshes and sandflats. The site contains a complete morphological and stratigraphic record of shoreline changes over the last 7000 years. Furthermore, the site is highly dynamic with landforms that are constantly moving and evolving. The site therefore has a potential, perhaps greater than any other part of the Highland coastline, for research into rates of contemporary change and comparison with the past. This IPA supports seven species of stonewort including some that are very rare in this part of Scotland.
Conservation Issues The eelgrass beds of the SSSI were monitored during 2004 and found to be in favourable condition, with visible reproduction of plants and virtually no smothering by surface algae. The saltmarsh habitat (of the SSSI) was monitored in 2001 and was found to be in favourable condition. Saltmarsh is a sensitive habitat and localised damage to the soft surface can take decades to recover. For example, the saltmarsh is showing signs of recovery from activities such as vehicle tracking and turf removal undertaken many years ago. One area of saltmarsh at Edderton Sands has been noted recently as actively eroding, but other saltmarsh habitats appear to be either increasing or stable. The sand dunes habitat was last monitored during 2004 and found to be in unfavourable condition for two reasons. Previous agricultural improvements such as ‘liming’ have caused a reduction in the area of the natural dune grassland habitats. Secondly, scrub and tree encroachment are reducing the area of this habitat. If left unmanaged, the heath will be lost and the site now requires active management to remove the existing dense banks of scrub and prevent further spread. Further reseeding or liming would not be appropriate management for this site. Further advice on management options for this site should be sought from SNH. Whilst reduction in grazing has helped to increase biodiversity in some areas, it has contributed to the encroachment of scrub on coastal heathland and the development of “coarse” grass species in some areas of species-rich grasslands. Some agricultural practices, such as liming and reseeding, have led to modification and loss of the natural dune grassland and heath communities. The population of pyramidal bugle has declined to just a few individual plants and is in unfavourable condition. Populations of bugle (>200 plants) once grew over dune habitats at a number of locations but the populations have declined significantly. This is thought to be due to herbicide spraying (spot-spraying weeds) as part of the golf course management and scrub encroachment. The remaining plants now have a small fence erected around them to prevent further spraying. The greenkeeping staff have also cut away gorse from a small area to one side of the current plants where it is hoped that new plants may germinate. During 2010, SNH, in partnership with Royal Botanic Gardens Edinburgh have planted >150 pyramidal bugle plants of local provenance back into areas of the site where they previously grew. These plants will be monitored by SNH to assess the success of this project. Heather has been affected by large outbreaks of heather beetle in the recent past. This has led to some mature heather stands being killed. Heather is expected to recover from such outbreaks through natural regeneration although this can be slow. Access and recreation within the terms of the Scottish Outdoor Access Code would appear to be largely compatible with protecting the nature conservation interests of the site. Disturbance to wildfowl and waders remains a potential issue, particularly with respect to dog walking, where dogs are not kept under proper control. Horse riders occasionally use the Dornoch beach and surrounding coast. Most of the time, this raises no concerns, but horse hoof prints leave a deep imprint on soft saltmarsh habitats. If these sensitive routes are used regularly, horse riding has the potential to cause extensive trampling damage to saltmarsh which could take decades to recover. In the past, there have been concerns regarding the unauthorised use of motor vehicles over the stabilised sand dunes and saltmarsh. Although the Dornoch Point area is now physically protected against habitat damage from 4-wheel drive vehicles through the installation of bollards, this area is still subject to occasional damage by off-road motor bikes. The saltmarsh habitats at Morrich More still show signs of damage from recent industrial use but it is expected that they will fully recover in time. Curved sedge, Carex maritima, has not been found on the site in recent years but overall the vascular plant assemblage is considered to be in a favourable condition. The dune grassland feature is in a favourable condition on Morrich More but unfavourable elsewhere in the SAC. The coastal dune heathland and dune habitats with juniper on Morrich More were, however, considered to be in an unfavourable condition when monitored during 2001-2004. Both habitats showed poor structural diversity and browsing damage was evident on juniper bushes The active natural processes on the site may lead to rapid changes in the relative position of the natural features and this may mean that the extent of some features reduces. This is an essential and positive attribute of the site. Climate change may influence these processes in future. Natural processes may also mean that the site will no longer support suitable habitat for curved sedge in future