Dunes, shingle and machair

Context

These habitats occur above the high water mark, but often in areas which are influenced by wave splash and sea-spray.  Salt-tolerant species are the characteristic colonisers of this habitat and the biotopes present are strongly influenced by sediment size as well as the degree of wave exposure of the shore.
 
Strandline communities are often present on moderately exposed sandy shores, particularly on flat, slightly mobile beaches with little or no human disturbance.  Under these conditions annual vegetation can develop on the accumulations of drift material rich in nitrogenous organic matter at or near the high water mark.  Characteristic vascular plants include sea sandwort Honckenya peploides, saltwort Salsola kali, and sea beet Beta maritima.
 
On the upper margins of the shore, three major supralittoral sediment habitat types occur: coastal vegetated shingle, sand dunes, and machair.
 
Shingle beaches are widely distributed around the UK coastline and tend to form in high-energy environments where the sea can pile up pebbles above the tide line.  There are five recognised types distributed around the UK: fringing beaches, spits, barriers, cuspate forelands and barrier islands.  Herb-rich open pioneer stages colonise the seaward edge with species such as sea-kale Crambe maritima, sea pea Lathyrus japonicus, thrift Armeria maritima, yellow horned-poppy Glaucium flavum and sea holly Eryngium maritimum.  Grassland, heath, scrub, and moss and lichen-dominated vegetation of old, stable, shingle occur further inland.
 
Distinct features within sand dune systems include fore dunes, yellow dunes, dune grassland, dune slacks, dune heath and dune scrub.  Factors such as stability and moisture retention in these different systems determine what species are present.  In mobile fore dunes, for example, typical species are marram Ammophila arenaria and, in northern areas of Britain, lyme-grass Leymus arenarius. Dune slacks, which are areas of wetland within the dune system, may have scarce plants such as fen orchid Liparis loeselii and petalwort Petalophyllum ralfsii.
 
Machair is a distinctive sand dune formation that is only found on the North and West coast of Scotland and in western Ireland.  The soils are made up of wind deposited shell-sand blown inland from coastal beaches and mobile dunes, which lie over impermeable rock.  The main habitats of machair are dry grassland, damp grassland, marsh and standing water and the vegetation is broadly described as a herb-rich sward.  Machair also supports a rich invertebrate fauna and large wader populations, for example on the Uists, Tiree and Coll.  These populations of waders are considered the most important in the north-west Palaearctic.
 
SSSIs can be notified if they qualify under criteria outlined in Sections 5 (dunes) and 6 (shingle) of Chapter 1 Coastlands of the Guidelines for Selection of Biological SSSIs.  In Northern Ireland, ASSIs are selected on a very similar basis – the Guidelines for the Selection of Biological ASSIs in Northern Ireland is an addendum to the SSSI guidelines rather than an alternative 
 

Summary statistics

  SAC A/SSSI Total
Favourable condition 46% 50% 49%
Main monitoring coverage E, S, W, NI E, S, NI  
Reported assessments 153 189 342
Completeness of assessments 89% unknown  
Distribution of features     UK
 

Number of assessments reported by country and site type

Country SAC SSSI/ASSI
England 71 70
Scotland 53 103
Wales 18 0
Northern Ireland 11 16
United Kingdom 153 189
 

Natura features

List of Natura 2000 interest features within this reporting category

Interest feature name  
Formal name Informal name No. of assessments reported Total no. of features % assessed
Annual vegetation of drift lines Annual vegetation of drift lines 10 12 83%
Atlantic decalcified fixed dunes (Calluno-Ulicetea) Coastal dune heathland 9 10 90%
Coastal dunes with Juniperus spp. Dunes with juniper thickets 1 2 50%
Decalcified fixed dunes with Empetrum nigrum Lime-deficient dune heathland with crowberry 2 2 100%
Dunes with Hippophae rhamnoides Dunes with sea-buckthorn 1 1 100%
Dunes with Salix repens ssp. argentea (Salicion arenariae) Dunes with creeping willow 13 14 93%
Embryonic shifting dunes Shifting dunes 20 22 91%
Fixed dunes with herbaceous vegetation ("grey dunes") Dune grassland 26 31 84%
Humid dune slacks Humid dune slacks 22 25 88%
Machairs Machair 8 8 100%
Perennial vegetation of stony banks Coastal shingle vegetation outside the reach of waves 12 13 92%
Shifting dunes along the shoreline with Ammophila arenaria (“white dunes”) Shifting dunes with marram 29 32 91%
 
Natura 2000 comprises Special Protection Areas (under the Birds Directive) and Special Areas for Conservation (under the Habitats and Species Directive). The list presented here includes all of the qualifying interest features under these Directives, and shows the proportion of these features for which a condition assessment has been made.
 

SSSI features

List of SSSI and ASSI interest features in this reporting category

Interest feature name  
Formal name Informal name No. of assessments reported
Coastal sand dunes Dunes with Salix repens ssp argentea (Salicion arenariae) 1
Coastal sand dunes Embryonic shifting dunes 2
Coastal sand dunes Fixed dunes with herbaceous vegetation 1
Coastal sand dunes Humid dune slacks 1
Coastal sand dunes Shifting dunes along the shoreline with Ammophila arenaria (“white dunes”) 1
Coastal sand dunes Shifting dunes along the shoreline with Ammophila arenaria (white dunes) 2
Coastal sand dunes Coastal sand dunes 1
Coastal vegetated shingle Coastal vegetated shingle 1
Coastal vegetated shingle Perennial vegetation of stoney banks 1
Coastal vegetated shingle Annual vegetation of drift lines 1
Fixed dunes with herbaceous vegetation (“grey dunes”) Fixed dunes with herbaceous vegetation (“grey dunes”) 1
Machairs Machair 32
Maritime cliff and slope Maritime cliff and slope 2
Perennial vegetation of stony banks Perennial vegetation of stony banks 1
Sand dune Sand dune 55
Shingle Shingle 16
Supralittoral Sediment Supralittoral Sediment 70
 
This list has not been fully standardised at a UK level yet. It is intended to show the principal constituent "feature types" for this reporting category.
 

Maps - distribution

UK distibution of reported interest features

Distribution of reported interest features.

Map showing the locations of the 10km squares in which at least one condition assessment has been reported. It does not show features that have not yet been assessed.

 

Maps - Natura

Distribution of SAC features showing assessments of favourability Condition of SAC features, with those currently reported as unfavourable-recovering shown as favourable
Current condition of SAC features
Distribution of SAC features showing assessments of favourability (where unfavourable-recovering is counted as unfavourable).
Condition of SAC features, with those currently reported as unfavourable-recovering shown as favourable
The implication of the unfavourable-recovering condition assessments is that at some point in the future these features should become favourable. This map shows the effect of that recovery by counting the favourable and unfavourable-recovering assessments together.

 

IMPORTANT NOTE: we do not have information on the timescale of the predicted recovery, which may be influenced by many past, natural and human related factors. A sustained sympathetic management regime is more likely to result in favourable condition being attained.

Key: Proportion of assessed features on 10km squares that are favourable:

Natura map legend - Key: proportion of assessed features on 10km squares that are favourable

 

Details of how these maps were produced

 

Maps - SSSI

Current condition of SSSI/ASSI features Condition of SSSI/ASSI features, with those currently reported as unfavourable-recovering shown as favourable
Current condition of SSSI/ASSI features
Distribution of SSSI/ASSI features showing assessments of favourability (where unfavourable-recovering is counted as unfavourable).
Condition of SSSI/ASSI features, with those currently reported as unfavourable-recovering shown as favourable
The implication of the unfavourable-recovering condition assessments is that at some point in the future these features should become favourable. This map shows the effect of that recovery by counting the favourable and unfavourable-recovering assessments together.

 

IMPORTANT NOTE: we do not have information on the timescale of the predicted recovery, which may be influenced by many past, natural and human related factors. A sustained sympathetic management regime is more likely to result in favourable condition being attained.

Key: Proportion of assessed features on 10km squares that are favourable:

SSSI map legend - Proportion of assessed features on 10km squares that are favourable

 

Details of how these maps were produced

 

Condition summary

Reporting category condition summary on Natura 2000 sites and SSSI

This lists the 10 different condition assessments and presents a bar chart showing the number of features within the SSSI series and the Natura 2000 series (either SPA for bird features or SAC for features other than birds). Note that for Natura 2000 we are able to estimate the number of features that have not been assessed during the 6 year reporting period - we are unable to do this for SSSI/ASSI because we do not have an overall list of notified interest features for these designations.

 

NB favourable unclassified and unfavourable unclassified have been used in this first six year cycle to get around difficulties in identifying trends in condition as common standards monitoring is implemented. It is expected that these categories will not be used for subsequent assessments of a feature.

 

Condition assessment - Natura 2000 features

The number and proportion of assessments for Natura 2000 (SAC and SPA) interest features falling into each of the condition categories
The number and proportion of assessments for Natura 2000 (SAC and SPA) interest features falling into each of the condition categories. Note that the �unfavourable� category includes all reports of unfavourable condition except �unfavourable recovering� which is shown as a separate segment.
 

Condition assessment - SSSI features

The number and proportion of assessments for SSSI/ASSI interest features falling into each of the condition categories
The number and proportion of assessments for SSSI/ASSI interest features falling into each of the condition categories. Note that the �unfavourable� category includes all reports of unfavourable condition except �unfavourable recovering� which is shown as a separate segment.
 

Adverse activities

The number of interest features where an activity has been reported as being implicated in the "unfavourable" condition of a feature
The number of interest features where an activity has been reported as being implicated in the "unfavourable" condition of a feature. More than one adverse activity may be reported for each feature.
 

Management measures

The measures summary bar chart lists the management measures relevant to the reporting category
For each "measure" the chart shows the number of interest features where that measure has been taken on a site to improve or maintain the condition of an interest feature. More than one measure may be reported for each feature assessed.
 

Interpretation

Overall, 49% of dune, shingle and machair features reported are in favourable condition.  This is below average for marine and coastal features, and just below the average condition for all features taken together, but above the average for habitat features.  50% of A/SSSI and 46% of SAC features reported are in favourable condition.  A further 13% of A/SSSI and 18% of SAC features reported are in unfavourable-recovering condition.  Dune heaths in SACs are generally in poor condition.  Dunes with Salix repens, although mostly unfavourable, are better catered for by the provision of management agreements.
 
Habitat management issues are the greatest cause of unfavourable condition for sand dune, shingle and machair features.  Most significant of the habitat management issues is under-grazing and lack of remedial management.  Lack of grazing leads to invasion by coarser grasses and scrub, and decline in quality of the habitat.  Securing grazing is complicated by intrinsic difficulties of stock management on many coastal sites and issues such as the quality of grazing.  Over-grazing can also be an issue.  Scrub and invasive species management plans may have long lead-in times and need long time periods to deliver results.
 
Management plans with the owners of sites help address these issues.  Agricultural grant schemes have an important role to play in this, but the figures indicate a disappointing level of application for these feature types.  More work needs to be done with partners and owners to improve take up of agri-environment schemes.
 
Inappropriate coastal management will affect shingle and sand dune habitats.  This can include disrupted shingle movements or sand supply, which interrupts longshore drift, or moving or reprofiling shingle ridges for flood management, which disturbs the habitat developing on the surface.  In these cases it will be non-conservation public bodies responsible for managing the habitat.  Many of these problems can only be addressed through strategic shoreline management plans and strategies.