YNYS GYBI SITE OF SPECIAL SCIENTIFIC INTEREST
What is ‘special’ about Glannau Ynys Gybi SSSI?
Glannau Ynys Gybi SSSI has 11 special features:
Vegetated coastal cliffs and cliff-top grassland
Lowland dry heath
Lowland wet heath
South Stack (Spathulate) fleawort
An assemblage of scarce vascular plant, including pale heath violet, golden samphire, rock sea-lavender and Portland spurge.
Golden hair lichen and ciliate strap lichen
Silver studded blue butterflies
As well as the features listed above, Glannau Ynys Gybi SSSI has other habitats/earth science features that contribute to the special interest. These include scrub, ponds and rock outcrops. This mixture of habitats is important for much of the wildlife including juniper, hay scented buckler fern, filmy ferns along with skylark, linnet, brown hare, a breeding seabird colony with razorbill, guillemot, puffin, fulmar, kittiwake and potential for the return of marsh fritillaries. Other features of interest include rockpools, overhanging rock, gullies and underboulder communities and their associated flora and fauna. These too are key components of the special interest of the site. Unless specified below, management of this site should aim to look after these habitats and species as well as the listed features of interest.
The cliffs around South Stack display some of the most magnificent exposures of folded rocks in Britain. They are particularly important to study the effect of folding and fractures on different rock types.
The exposed geology of the site should continue to demonstrate fine exposures of folded Precambrian rock. These geological features should remain visible and accessible to geologists.
The vegetated coastal cliffs should remain largely undisturbed and support the endemic South Stack fleawort, golden samphire, rock sea lavender, hay scented buckler fern, juniper, ciliate strap-lichen and golden hair lichen.
At least 70% of the site should be covered by lowland and coastal heathland. The habitat should be of good quality characterised by of heather and western gorse with crossed leaved heath, deer sedge and Sphagnum moss in wet areas, spring squill near the coast and abundant short turf and open ground. It should provide habitat for a wide range of birds including skylark, linnet, stonechat and whitethroat, reptiles and insects including the silver studded blue and the potential for marsh fritillary to re-establish.
In some areas where there are rocky outcrops in heathland, the habitat should be favourable for the spotted rock rose which occurs in the thin crusts of soil with lichens and mosses and short grasses. Areas of herb rich neutral grassland may be maintained for their floristic, invertebrate and chough feeding value
Sixteen pairs of chough currently nest on the cliffs and a breeding population of this size or greater should be resident, aided by management of feeding zones in the surrounding area.
A breeding seabird colony with guillemot razorbill and puffins along with fulmar, kittiwake and peregrine, should be maintained.
What management is needed on Glannau Ynys Gybi SSSI SSSI and why?
Although Glannau Ynys Gybi SSSI is an excellent place for wildlife and geology it will only remain so if the necessary management continues. CCW’s aim is to work with you to ensure that this management is carried out.
What does this mean in practice?
There are many factors that could damage the special features at Glannau Ynys Gybi SSSI if they are not properly managed. These are the ones we regard as most important:
Geology (Folded Precambrian rocks)
Students and researchers need access to study the rocks exposed around South Stack. Access should be maintained to the coast and heath at South Stack, including South Stack island and steps, in so far as this does not conflict with breeding birds.
Any activities that might obscure the rock exposures, for example the dumping of earth, spoil or other waste materials, the buttressing and/or battering of the rock faces, or building works such as new steps should be avoided.
Vegetated coastal cliffs
Exposure to sea spray
No management implications.
Lack of disturbance
Discourage any “cleaning” of vegetated new routes by climbers.
Maintain absence of livestock (especially goats) on cliffs or very light grazing pressure as appropriate.
Competition from smothering species
Avoid invasive alien species such as purple dew plant or Hottentot fig
Low soil fertility helps heather and western gorse to compete against more aggressive agricultural grasses.
Avoid any fertiliser or slurry application or use of silage
Light grazing encourages the development and maintenance of dwarf shrub heath. Cattle and horses are to be preferred as they are less selective in their grazing than sheep, permitting more plants to flower and set seed, whilst also breaking up dense clumps of gorse (although sheep may be better than nothing for a time). They also produce minor poaching of the ground enabling seedlings to establish and providing a feeding niche for chough. Grazing animals help create natural firebreaks.
Maintain light grazing wherever possible. Periodic heavier grazing may be required on a spatial or temporal patchwork to meet chough requirements (4.4). Grazing may not be possible in certain areas or at certain times due to constraints such as health and safety, stock control problems etc.
Controlled small patch burning rejuvenates heather and gorse, can help reduce soil fertility and provides microhabitat for spotted rockrose, silver studded blue and feeding chough. Uncontrolled large fires, particularly in summer, damage invertebrate and reptile communities and re-establishment becomes difficult. Undertake controlled patch burning where appropriate and feasible given the constraints of thin soil, invading bracken, weather conditions, health and safety and adjacent properties. Mowing small patches may be used as an alternative to burning where appropriate. Mown or back-burnt firebreaks may be necessary.
Patches of scrub provide nest and foraging areas for stonechat, whitethroat etc
Maintain up to 5% scrub cover in small blocks on heathland.
Caves and sheltered ledges provide nest sites.
Ensure undisturbed breeding caves and ledges during the breeding season.
Short unimproved turf that provides accessibility to soil invertebrates is vital to support chough. Cloddiau are important feeding sites. The maintenance of the breeding population of chough may require feeding areas beyond the present boundary of the SSSI.
Outwinter livestock wherever possible and avoid use of Avermectins in order to provide dung suitable for insects.
Establish appropriate grazing levels. These may be higher than normally required for heathland maintenance and a programme of heavier grazing with periods of recovery years on a patchwork pattern may be required.
Maintain accessibility to cloddiau by encouraging bank top fencing rather than basal fencing.
South Stack Spathulate fleawort
Requirements as for vegetated cliffs
Spotted rock rose
Requirements as for heathland. Flowering plants of spotted rockrose are susceptible to sheep grazing in summer.
Avoid sheep grazing on rock rose areas in summer.
Avoid repeated burning of heathland areas containing rock rose
Breeding seabird colony (razorbill, guillemot, puffin, fulmar, kittiwake)
Breeding seabirds require secure nesting sites, free from human or predator disturbance, and a reliable food supply. Nesting occurs extensively on the steep southern slopes and ledges 1 February to 31 July.
Maintain voluntary restraint agreements with climbers, canoeists etc.
Golden hair lichen and Ciliate strap-lichen
Physical disturbance and fire
Maintain voluntary restraint on route “cleaning” by climbers.
Avoid fire on thin maritime turf.
Silver studded blue
Needs young food plant (heather, gorse, birds foot trefoil)
Maintain early heath succession phase by light grazing and/or controlled burning.
Warm open ground to encourage black ants which form symbiotic protective relationship
Maintain controlled patch burn regime.
Establish controlled grazing.
Our knowledge of wildlife is far from complete. It is possible that new features of value may appear and new management issues may arise in the future, whilst other issues may disappear. This statement is written with the best information we have now, but may have to change in the future as our understanding improves. Any information you can provide on the wildlife of your site, its management and its conservation would be much appreciated.
If you would like to discuss any aspect of your SSSI, or have any concerns about your SSSI, please contact your local CCW office.
Your local office is;
Cyngor Cefn Gwlad Cymru/Countryside Council for Wales
Llys y Bont,
Ffordd y Parc,
Gwynedd, LL57 4BN,
Fax: 01248 679259