Nature and Wildlife -
National Vegetation Classification Survey -
2003/2004 Summary
The complex of strandlines foredunes, sand hills, slacks, dune plains and dune heaths along the Sefton Coast forms the largest single dune system in England. Between April 2003 and July 2004 the accessible sand dune vegetation resource of the Sefton Coast was surveyed and mapped, applying National Vegetation Classification (NVC) definitions. The survey also covered vegetation types other than sand dune communities, including areas of swamp, strandline, mesotrophic grassland communities, acid grasslands, mire, heath and scrub/woodland, included in the intricate mosaic over the areas of blown sand remaining outside agricultural use and residential development.
The area covered extends from Hesketh Golf Course in the north (SD 353 195) south through Formby Point to Crosby Marine Park (SJ 315 973) taking in a series of nature reserves, SSSIs, golf courses and land under military use.
Along Marshside, Birkdale 'green beach' and the Alt estuary dune habitats abut areas of salt-marsh mapped as part of the Ribble and Alt Estuaries NVC Survey in 2002.
The main aims of the survey are to provide current descriptions of sand dune and associated habitats at each site and to map the vegetation communities over the entire Sefton Coast. Fieldwork was carried out using a Geographical Positioning System to map the community boundaries, quadrats and target notes.
Positional data were recorded, via PocketGIS, onto a Husky field computer. Vegetation data were recorded onto a second portable computer using the Plant Entry System developed specifically for rapid species data entry in the field as well as automated analysis of raw data.
A major objective of collecting data for the whole coast is to allow comparison between current findings and the results of the previous coast-wide NVC survey conducted in 1988/89.
Vegetation boundaries, mapped in the field and verified by aerial photographs, were digitised in MapInfo v 6.5. As well as being accessible in GIS format, paper maps were also printed for each dune area, presented at a scale of 1:2500.
The sand dune habitat resource, covering 1970 ha, mapped by the survey was sub-divided into polygons numbered from 1 to 5369. Across the range of polygons 2513 quadrats were recorded, sampling the full range of vegetation communities encountered. TABLEFIT, V1.0 was employed to assist in comparing Sefton data with the NVC-defined communities and sub-communities. As well as the NVC community codes the equivalent CORINE code for each vegetation type is also presented.
A total of 563 vegetation categories (matching 61 broad NVC community types) was mapped across the Sefton dunes; including mosaics, transitions and other features such as bare sand and open water.
Overall the most widespread vegetation type recorded was SD7 Ammophila arenaria-Festuca rubra semi-fixed dune community, with a total of 466 ha (23.6% of the area surveyed) compared to 340 ha reported in 1988/89.
The most notable decrease in area of any dune community type between 1988/89 and 2003/4 was for SD8 Festuca rubra-Galium verum fixed dune grassland. This is an integral part of the UKBAP priority Coastal Sand Dunes habitat but in 2003/4 only 8 ha of this type was mapped, compared to 94 ha in the 1988/89 Sefton survey. This large change is presumably partly due to the increased area of SD7 communities, where blowing sand from the eroding frontal ridge settles over former fixed dune grassland, suppressing the field layer herbs and bryophytes and stimulating growth of the marram. The change may also be in part due to differences between survey techniques.
A widespread observation over the whole dune system, with the exception of the extreme seaward edge, is the continuing high level of dense neutral vegetation over areas where typical SD8 or dry slack communities might be expected. Though the spread of scrub over the dune system, since the demise of rabbit populations following myxomatosis, is well documented it appears that false oat-grass (Arrhenatherum elatius) is also a significant colonist of dune grasslands.
This species is a natural component of the dune vegetation and where there is some local increase in available plant nutrients on dunes then SD9 Ammophila arenaria - Arrhenatherum elatius swards tend to develop. SD9 has increased throughout the dune system, from 13 ha in 1988/89 to 27 ha in 2003/4; there is also a continuing significant occurrence of MG1 Arrhenatherum elatius mesotrophic grassland swards, usually with marram (Ammophila arenaria) still surviving in a dense mix of typically coarse neutral species. From the 1988/89 report there was a total of 120 ha of MG1 community, over 2003/2004 110.50 ha of this type was recorded. Abundance of false oat-grass-dominated community has therefore not increased since the 1988/89 survey, but false oat-grass remains an important factor in the dunes and appears to be occurring more frequently within other SD communities.
Most marked changes in extent of SD community types
| SD | Types | 1998/89 | 2003/04
| | SD2 | 2.86 ha | 0.6 ha | 79% decrease |
| SD5 | 19.27 ha | 5.43 ha | 72% decrease |
| SD6 | 123.65 ha | 95.11 ha | 23% decrease |
| SD7 | 339.57 ha | 465.65 ha | 37% increase |
| SD8 | 93.95 ha | 7.87 ha | 92% decrease |
| SD9 | 13.28 ha | 26.96 ha | 103% increase |
| SD10 | 4.12 ha | 41.79 ha | 914% increase |
| SD12 | 39.41 ha | 7.52 ha | 81% decrease |
| SD13 | 7.59 ha | 0.15 ha | 98% decrease |
| SD15 | 54.82 ha | 34.58 ha | 37% decrease |
| SD16 | 46.77 ha | 59.01 ha * | 26% increase |
| SD17 | 1.85 ha | 7.66 ha | 314% increase |
| SD18 | 39.57 ha | 18.78 ha | 53% decrease |
| SD19 | 39.34 ha | 3.11 ha | 92% decrease |
* includes 38 ha of dry SD16 dune type and 21.01 ha of damp SD16 slack types.
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