Annex 08: Spey Bay 

Site Name: - Spey Bay and Kingston Shingle

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Location

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Introduction

The shingle of the wider Spey Bay is an example of a shingle apposition beach which has been laid down against the Binn Hill cliffs, believed to have been cut in 25ft raised beach times. The full Spey Bay site lies between the mouths of the Lossie in the west through to Spey mouth in the east. The apposition beach consists of a series of clearly defined shingle ridges which were laid down with a successive lowering of sea level following the last ice age and are thought to date from 8000 years ago. The area includes Culbin Sands and the Culbin Shingle Bar to the west and the Spey Bay/Kingston shingles in the east.

The shingle which lies at or near the mouth of the river Spey (see location map above) can be divided into two sections:

1. The modern deposits which continue to be brought down the river and are reworked at the river mouth by the action of the river and the sea;
2. The fossil deposits to the west of the village of Kingston, which were probably laid down during the early post-glacial period.

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Spey Bay

The shingle east of the mouth of the Spey is thought to have been part of a spit, deflecting the course of the Spey to a mouth 1.5 km west of its current position. The foreshore comprises a steep storm ridge of bare shingle with a slack area behind which gives way to the raised beach of shingle ridges behind. At the mouth of the Spey lateral drift moves sediments westwards and the beach immediately to the west of the river mouth is also suffering from coastal erosion. As a result of this periodic intervention to restore alignment of the river mouth and prevent erosion of the west bank near to Kingston, which has been periodically flooded in the past is undertaken. More generally, there have been other fairly substantial erosion control projects in the Spey.

Intervention is carried out at intervals of about 25 years in what appears to have been a relatively ad hoc manner. Although records of the work have been made they are held in disparate locations and there has not necessarily been any follow-up monitoring work to assess the success of any given scheme. In order to access the requirements for the conservation management of this site a study of the geomorphology and management of the two Sites of Special Scientific Interest, the River Spey and Spey Bay have been undertaken (Gemmell et al. 2001).

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The sediment budget

Modelling of the contribution of shingle to the sediment budget from the River Spey suggest that it contributes 8,000 m³ to the coastal system annually. A further 16,760 m³ is made available by recession of the beach. Nearly 5,000 m³ is deposited within the existing system to the west (down drift side) with the rest being lost. The report indicates that the continued integrity of the beaches and hence their ability to protect the properties depends on the "ongoing supply of sediment derived from upstream erosion and channel migration.". In the past the Sites of Special Scientific Interest (the river system and the coastal shingle) have suffered from ad hoc decisions, which appear to have had an adverse impact on the sites. It makes several recommendations:

1. The system as a whole needs to be managed to "conserve the sediment transport and supply";
2. Works which interfere with the exchange of material should not take place unless they can be shown not to impact on the system or where there is extreme threat to life or property;
3. Where works are proposed they should, where possible use onsite materials, rather than rip-rap;
4. A management strategy for the whole site (including both the riverine and coastal SSSI) is required.

These general points are applicable to other sites where there is significant movement of shingle both offshore and alongshore.

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Kingston vegetated shingle

Kingston shingle, which lies to the west of the River Spey in Scotland, is another important area for vegetated shingle. It is a site considered to be of national importance in a Great Britain context. Unlike the adjacent area of Spey Bay it is a more stable structure with only the seaward ridge being subject to the forces of erosion and deposition as a result of wave and storms. Interestingly, this site does not support any pioneer flora as a result of the high-energy nature of the beach, which has a maximum fetch of 400km to the north east (ITE 1982).

The particular interest of this site, in the context of the Shingle Management Guide, lies in the areas of disturbed shingle where shingle extraction destroyed much of the ridge structure. Gravel mining at this site was started in 1935 with extraction from the bare shingle foreshore and later extended such that an estimated 60% of the shingle area has been reduced to damp shingle lows, with ridges of waste shingle perpendicular to the alignment of the natural ridges. The lows are around 2-3 m below the general beach level. The result of this action has been to lower the level of the shingle, though not below the water table. The resulting communities appear more like dune ‘slacks’ probably as a consequence of the close proximity of the water table and near the sea, saline intrusion.

Lichen evidence suggests that active mining ceased in this western region 30-40 years ago. These areas of ‘slack’ vegetation grade into areas of shingle heath. At the landward limit of the shingle ridges, fen and marsh grade into shingle scrub. The plant communities which have established in these hollows are probably unique on areas of shingle in Great Britain at least and rich in a wide variety of rare and local species.

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Importance of the site for vegetated shingle restoration

This site shows that given time (30-40 years) important plant communities can colonise areas of wet shingle and increase the overall biodiversity of plants on a given site. The plant communities including the transitions to heath, wetland and scrub also support a rich assemblage of invertebrates. Details of the plant communities are available in the Description of the coastal vegetated structures of Great Britain Appendix 2 Scotland (Sneddon & Randall 1994a) given below. The site is also important as an example of a more or less complete sediment system with contemporary inputs, derived from land-based sources in this case delevered by a river system.

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The plant communities

The levels of disturbance of this site, along with its size, have led to the development of a particularly varied flora with certain communities unique to shingle at Kingston. The community types range from maritime grasslands through heathlands and fen communities to scrub and carr communities.

Maritime vegetation

The slack immediately behind the storm crest at the western end of the site supports interesting maritime grassland comprising a Festuca rubra dominated herb rich grassland. The maritime herbs Armeria maritima and Plantago maritima are the additional constants but this community is more diverse than would normally be associated with a Festuca - Armeria - Plantago grassland with Empetrum nigrum as a major associate. Anthyllis vulneraria, Plantago lanceolata, Potentilla anserina, Trifolium repens and Sagina nodosa are the key herb associates while Viola riviniana, Rhinanthus minor and Gentianella campestris are found as infrequent associates.

This community extends along the foreshore even within the pine plantation, although here there are some areas which are poorly-drained and where the grassland is replaced by wetland communities. In the far west, an area in the slack is occupied by a Schoenus nigricans - Calliergon cuspidatum community with Potentilla anserina, Hydrocotyle vulgaris, Agrostis canina and Empetrum nigrum as major associates. The maritime nature of the wetland is illustrated in the minor presence of Juncus gerardii. This community is unique, on shingle, to Kingston and as such was not included in the main classification data. This area gives way at its western limit to a Festuca rubra - Schoenus nigricans mixed grassland with Poa pratensis and Agrostis canina. The major herb species in this instance include Salix repens, Trifolium repens, Erica tetralix, Empetrum nigrum and Anthyllis vulneraria. This clearly represents a transition from the Schoenus community to a Festuca rubra grassland seen elsewhere in the slack.

Excavated shingle

The Salix repens community is also found occupying one of the depressions on the eastern section of the site in old gravel workings. In this case the key indicators are Salix repens and Carex panicea and the mosses Campylium stellatum and Caliergon cuspidatum. Juncus bulbosus and Juncus balticus are the major associates along with Carex nigra and Trifolium repens. Stachys arvensis, Prunella vulgaris and Pedicularis palustris are among the major herb indicators while Galium aparine, Ranunculus flammula and Epilobium palustre are occasional associates. In places, Schoenus nigricans, which is found in small quantities throughout the community, becomes locally dominant, along with Scorpidium scorpoides and Hydrocotyle vulgaris thus serving as indicators of wetter conditions within this community. This is a less maritime version of the Schoenus community described earlier. There is some invasion of Salix cinerea and Betula pendula within this community.

It is the wetland communities which are particularly interesting at this site with a small inland area supporting a Juncus effusus dominated community with Agrostis stolonifera, Holcus lanatus and Festuca rubra as minor constants. There is a minor herb component in this community with Valeriana officinalis, Ranunculus scleratus, Cardamine pratensis and Galium palustris as infrequent associates. This community occupies a poorly drained area round the eastern end of Stripe burn with approximately 40% open water in each quadrat, and the water to a depth of 20 cm. While such a situation would not normally be associated with a shingle habitat, there was shingle below the water and mud. However, it implies the presence of an impermeable layer below the shingle.

A separate grassy heathland community is found in the excavated area where the excavation ridge structure is still clearly visible. The importance of microtopography in influencing vegetation is seen in this area. The ridges support a Festuca rubra - Ulex europaeus - Rosa pimpinellifolia - Cladonia impexa species-rich heathland community. The major grass associate in this case is Anthoxanthum odoratum with Agrostis capillaris and Aira praecox found frequently in association.

The bryophyte component is dominated by Eurynchium praelongum, Pleurozium schreberi and Rhytidiadelphus triquetrus with Dicranum scoparium and Polytrichium piliferum as minor associates. A large range of Cladonia spp. lichens are found in this community, but the most important species are C. arbuscula, C. rangiformis, C. chlorophea and C. cervicornis. There are relatively few herb associates in this community with Hypochoeris radicata and Crepis capillaris found frequently but in small amounts while Jasione montana is an occasional addition.

This contrasts with the community found in the lows between these excavation ridges, and in the older western excavations which clearly offer wetter environments. In this instance the community is characterised by the constant presence of Festuca rubra, Anthoxanthum odoratum and Plantago lanceolata with Ulex europaeus and Rosa pimpinellifolia continuing to be present but in a minor role. This assemblage is less a heathland than a herb rich grassland with Thymus arcticus praecox, Teucrium scorodonia, Viola hirta and Lotus corniculatus as the major herb associates while Empetrum nigrum, Jasione montana, Erica cinerea and Erica tetralix are found infrequently throughout the community. There remains a lichen component in the assemblage but in this case it is Cladonia ciliata, C. coniocrae and C. uncialis which are present in small quantities.

Grasslands

The major grassland community found inland, in the east of the site may be described as mixed grassland with an important herb and bryophyte component. The key indicator species are Agrostis capillaris, Festuca rubra, Poa pratensis and Holcus lanatus along with Peltigera canina an indication of the generally stable nature of this grassland. The major herb associates include Cerastium semidecandrum, Jasione montana, Anthyllis vulneraria, Thymus arcticus praecox, Hieracium pilosella and Lotus corniculatus found in varying amounts. Bryophytes provide a major element of the cover with Pseudoscleropodium purum, Polytrichium piliferum, Ceratodon purpureum, Rhytidiadelphus squarrosus and Dicranum scoparium most frequently sampled. Other than Peltigera canina, the major lichen species is Cladonia rangiformis, with C. furcata and C. cervicornis found in lesser amounts. A less diverse version of this Agrostis capillaris grassland is found on the disturbed area used for parking behind the storm crest in the east. In this case the Agrostis capillaris mixed grassland is found in association with Plantago coronopus and fewer herbs.

This grassland is often found in close proximity to scrubby grassland characterised by the constant presence of Ulex europaeus, Rubus fruticosus and Eurynchium praelongum with Rosa pimpinellifolia and Teucrium scorodonia as frequent associates. While Ulex is a constant, it does not dominate in the same way as is common on shingle. This is a scrubby grassland with Festuca rubra, Poa trivialis, Arrhenatherum elatius, Agrostis canina and Holcus lanatus as the key gramineae species. While the shade tolerant Eurynchium praelongum is the most important moss species, Rhytidiadelphus triquetrus and Pseudoscleropodium purum are occasionally found in this assemblage. This community covers much of the site extending back to the ridges at the rear of the site.

Scrub

Another assemblage which is a scrubby community is found behind the storm crest on those areas which were not excavated, or on the higher ridges within past excavations. This is a Ulex heathland with Erica cinerea, Calluna vulgaris, Anthoxanthum odoratum and Festuca rubra as minor constants. This community is again more diverse than most Ulex communities with a major herb content including Plantago lanceolata, Lotus corniculatus, Hypochoeris radicata, Rosa pimpinellifolia, Potentilla erecta, Achillea millefolium and Viola hirta as common associates. Empetrum nigrum, Teucrium scorodonia, Jasione montana and Cytisus scoparius are found infrequently throughout this community.

In some areas the Ulex is less important and the Calluna vulgaris becomes dominant within this community. This change is accompanied by an increase in the importance and diversification of the lichen flora with Cladonia impexa, C. cervicornis, C. furcata and C. chlorophea as the main lichen species. This slight shift towards a more heathland type of community is seen on the lower area south of the track which is more likely to flood.

There is some invasion of Pinus sylvestris and Salix cinerea at the south western edge of the community, with seedlings having become firmly established.

There is a re-emergence of the Ulex - Erica - Calluna heathland with Festuca rubra and Empetrum nigrum as additional constants, on a ridge found at the western end of the slack. This ridge is almost perpendicular to the storm crest and either represents past human disturbance. The well-developed lichen flora at this site suggests that this area has been stable for some considerable length of time. Juniperus communis is an infrequent associate in this community.

Undisturbed areas

Much of the largely undisturbed areas at Kingston support Ulex dominated scrub, best illustrated immediately behind the shingle slack, close to the edge of the plantation. This scrub is characterised by the constant presence of Ulex europaeus, Rubus fruticosus, and Eurynchium praelongum with Rosa canina and Teucrium scorodonia in minor amounts. Agrostis capillaris and Holcus lanatus are often found in association with the scrub species. This particular community, close to the storm crest, is consistently more diverse than the similar community found towards the rear of the site, which is presumably older. Here, the dominance of Ulex (Domin score 9-10) is such that there are few associates other than Eurynchium praelongum and Rubus fruticosus found in small quantities.

The relatively diverse Ulex grassland is also found within the plantation, firstly near the range at the seaward edge of the site, an area which appears to be relatively undisturbed in recent times.

A slightly different community is, however, found in small patches within the plantation where areas have been left undisturbed. Here the Ulex is a major constant along with Holcus lanatus, Agrostis capillaris and Festuca rubra. Additional minor constants include Rosa pimpinellifolia, Anthoxanthum odoratum, Arrhenatherum elatius and Hypochoeris radicata. This is a herb rich community with Cerastium fontanum, Teucrium scorodonia, Polygala serpyllifolia, Galium verum, Viola riviniana and Potentilla erecta as frequent associates.

An additional, and very different, scrub community, found at the rear of the site along the edge of the unvegetated shingle ridges, is a Pteridium aquilinum - Prunus spinosa - Rubus fruticosus community with a particularly high moss content with particular emphasis on Rhytidiadelphus triquetrus, Hylocomium splendens and Pseudoscleropodium purum with a minor role played by Pleurozium schreberi, Dicranum scoparium, Eurynchium praelongum and Ceratodon purpureum. Grass associates within this scrub assemblage include Arrhenatherum elatius, and Holcus lanatus. The Prunus scrub is more characteristic of north-western shores and so it is interesting to note its presence at Kingston.

This community is found at the edge of a community which is largely confined to this site, being typical of conditions wetter than those normally associated with shingle. It is a Salix cinerea - Deschampsia cespitosa - Pseudoscleropodium purum damp woodland community which occupies the lows between the older, bare shingle ridges at the rear of the site. This is the wetland extreme version of this community which illustrates a moisture gradient across the site. In this case there are very few associated species other than epiphytic lichens such as Evernia prunastri or Hypogymnia physodes, because even in late summer open water accounts for 95% of the area of each quadrat.

In drier areas this community develops into a Salix cinerea - Deschampsia cespitosa - Rubus fruticosus wetland scrub with Rosa canina, Rosa pimpinellifolia, and Prunus spinosa as associated scrub species. With no open water, much of the ground cover is provided by bryophyte species, in particular, Dicranum scoparium and Hypnum cupressiforme. The continuing influence of the water table on this community is seen in the constant, if minor, presence of marsh herbs, e.g. Galium palustris and Epilobium palustris, along with other herb species such as Potentilla erecta and Viola riviniana. Betula pendula is found occasionally in this community, in the drier areas.

These two communities represent the extremes of a moisture gradient but the largest area of the site is occupied by a community, which is basically wet Salix cinerea woodland but with less open water and, hence, limited development of an understorey. This middle community is characterised by the constant presence of Salix cinerea, Deschampsia cespitosa and Equisetum arvense with the epiphytic lichens Evernia prunastri and Parmelia sulcata. Juncus effusus and Holcus lanatus are found as frequent associates, along with a locally high herb content (where there is little open water). The herbs found here include Callitriche stagnalis, Ranunculus scleratus, Galium palustris, Cardamine pratensis and Myosotis sylvatica.

A separate Salix dominated community is characteristic of the dry shingle ridges which are found intact in the central section of the site. This community is a Salix - Betula - Calluna mixed heathy woodland with Empetrum nigrum, Festuca rubra and the lichens Peltigera canina and Evernia prunastri as minor constants. Additional heathland associates include Rosa pimpinellifolia, and Erica cinerea, while Erica tetralix and Vaccinium myrtillus are only occasional associates. Ulex europaeus is also an occasional associate; however, in some areas this species becomes locally dominant. Occasional grassland species include Agrostis capillaris, Holcus lanatus and Deschampsia cespitosa.

This may represent an area of heathland which is maturing through the invasion of Salix and Betula which do not yet provide the dense cover to shade out such associates.

A second Pteridium community occupies the area on the rifle range where much scrub has been cleared by hand. This community gives an interesting insight into the process of vegetation regeneration under such a regime. In this instance the consequent community is a Pteridium aquilinum dominated heathland. The Pteridium aquilinum is found with Deschampsia flexuosa, Calluna vulgaris and Pseudoscleropodium purum as the major constants. Key additional associates include Rosa pimpinellifolia, Ulex europaeus, Hypogymnia physodes and Teucrium scorodonia. The additional bryophyte species are Hylocomium splendens, Eurynchium praelongum and Hypnum cupressiforme while infrequent gramineae components include Agrostis canina and Anthoxanthum odoratum. Betula pendula and Rubus fruticosus are infrequent associates illustrating the regeneration of scrub in this community.

The importance of microtopography is once again seen here with the mixed Pteridium aquilinum community described above giving way to a Juncus conglomeratus - Carex flacca - Nardus stricta dominated community in depressions between ridges. This area was too small to map at his general level but is interesting to note nonetheless.

A slightly different woodland community is encountered within the plantation. This may reflect direct planting or that the plantation may have provided the seed source. This woodland comprises a Betula pendula canopy with Pteridium aquilinum, Deschampsia flexuosa and D. cespitosa as the major understorey indicator species. A major role is, however, also played in the understorey by bryophytes with particular emphasis on Rhytidiadelphus triquetrus, Pseudoscleropodium purum, Pleurozium schreberi, Dicranum scoparium and Hylocomium splendens. Here too, heathland elements are seen in the community with Calluna vulgaris, Rosa pimpinellifolia, Erica cinerea and Festuca ovina as minor constants.

The final community represented at this site is a Calluna vulgaris - Hypogymnia physodes - Empetrum nigrum - Cladonia impexa heathland. This is found on ‘islands’ of vegetation which occur on the otherwise bare shingle which has been left unplanted within the plantation borders. Erica cinerea, Thymus arcticus praecox and Rosa pimpinellifolia comprise the key herb associates while both the abundance and diversity of the bryophytes form a major component within this community. Rhytidiadelphus triquetrus, Polytrichium piliferum, Pseudoscleropodium purum and Dicranum scoparium are commonly associated with this vegetation unit.

Figure Spey Bay 01. An ‘island’ of undisturbed vegetation on shingle

Islands of vegetation

There appears to be some development of this community, seen on certain "islands" of vegetation (Figure Spey Bay 01), where the heathland species and bryophytes are constant throughout but the Rosa pimpinellifolia becomes a more important element and the importance of scrub is reflected in the additional constant presence of Juniperus communis. These areas may be considered a more mature sub-community of the original heathland.

These ‘islands’ of vegetation are particularly hard to map on this scale but may provide an important insight into the process of vegetation change on shingle. It would seem that the stochastic presence of moss, lichen or to a lesser degree Teucrium scorodonia, allows the establishment of grass species, then herbs, which enables the development of heath species such as Calluna vulgaris and finally scrub (Ulex europaeus and Juniperus communis). These species seem to emulate the role of Cytisus scoparius in Scott’s (1965) model at Dungeness.

The presence of scrub in the centre of ‘islands’ suggests the opposite of a classical gap phase succession theory (Whitmore 1990) with development taking place in the older centre while the outer edges are the youngest part of the island representing the colonising stage. These islands are an interesting topic for further research to assess the rate of expansion and to test the validity of Salix cinerea woodland as the next stage in the sequence.

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References

Gemmell, S.L.G., Hansom, J.D. & Hoey, T.B., 2001. The Geomorphology, Conservation and management of the River Spey and Spey bay SSSIs, Moray. Research, Survey and Monitoring Report No. 57 , Scottish Naturural Heritage.

ITE, 1982. Survey of Site 76 Spey Bay (West). Report, Institute of Terrestrial Ecology, Monks Wood.

Sneddon, P. & Randall R.E., 1994. Vegetated shingle structures survey of Great Britain: Appendix 2 - Scotland. Joint Nature Conservation Committee, Peterborough.

Scott, G.A.M., 1965. The shingle vegetation at Dungeness. Journal of Ecology, 53 : 21-31.

Whitmore, T.C., 1990. An Introduction to Tropical Rainforests. Clarendon Press, Oxford.

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