Ebbor Gorge

Site of Special Scientific Interest · 51.2350, -2.6808

Condition (Natural England)

Unfavourable Recovering (5) Favourable (1)
UnitFeatureConditionArea (ha)Assessed
ST521487 Unfavourable Recovering 8.65 2010-08-10
ST525486 Favourable 46.21 2010-08-10
ST526484 Unfavourable Recovering 4.69 2009-11-26
ST527480 Unfavourable Recovering 4.69 2009-11-26
ST531485 Unfavourable Recovering 4.69 2009-11-26
ST531486 Unfavourable Recovering 2.63 2009-11-26

Geology & landscape

Geological Feature: Cave / Cavern, Gorge / Ravine · Geological Period: Carboniferous · Rock Type: Carboniferous Limestone, Limestone, Millstone Grit

Landscape processes: Fluvial, Karst

Description

Description Ebbor Gorge lies on the south west facing slope of the Mendip Hills and consists of a steep sided ravine cut into Carboniferous Limestone. A stream issuing to the west of the site runs down the tributary valley of Hope Wood before joining the main gorge. Millstone Grit and Lower Coal Measures form an impermeable floor to this valley. The soils are well drained, fine and silty from the Nordoch series or loamy of the Crwbin series. They are of very variable depth with frequent exposures of rock on brows and steep valley sides. The majority of the site consists of calcareous ash woodland with a varied age and canopy structure, currently maintained by rotational coppicing and selective felling. The canopy is dominated by ash Fraxinus excelsior with oak Quercus robur varying in density from co-dominant in Hope Wood to virtual absence from central areas of the Gorge. Local stands of beech Fagus sylvatica, field maple Acer campestre, whitebeam Sorbus sp and hornbeam Carpinus betulus occur throughout the site. hazel Corylus avellana dominates the under storey and has been coppiced over a wide area. A variety of associated species include dogwood Cornus sanguinea, spindle Euonymus europaeus, wayfaring tree Viburnum lantana and guelder rose Viburnum opulus and wild privet Ligustrum vulgare. The ground flora is indicative of the calcareous nature of the site, with dog's mercury Mercurialis perennis being locally dominant. Many of the associated species are characteristic of ancient woodland. wood anemone Anemone nemorosa and bluebell Hyacinthoides non-scripta are both locally abundant. sanicle Sanicula europaea, primrose Primula vulgaris, pignut Conopodium majus, wood sedge Carex sylvatica, moschatel Adoxa moschatellina and opposite leaved golden saxifrage Chrysosplenium oppositifolium are also present. The valley of the main gorge is humid and provides ideal conditions for fungi and ferns. It contains a substantial assemblage of bryophytes with over 120 species recorded including the nationally rare Bryum canariense and very rare Amblystegium confervoides. In addition, rich communities of lichens occur on limestone outcrops and as epiphytes on older trees giving the Gorge in excess of 150 lichen species. Extensive areas of unimproved, rabbit grazed grassland occur at the top of the Gorge supporting a typical calcareous flora of common rose Helianthemum nummularium, fairy flax Linum catharticum, marjoram Origanum vulgare, wild thyme Thymus polytrichus, large thyme T. pulegoides, common milkwort Polygala vulgaris, salad burnet Poterium sanguisorba, carline thistle Carlina vulgaris and quaking grass Briza media. Leaching on the upper slopes gives rise to more acid tolerant flora such as European gorse Ulex europaeus and bell heather Erica cinerea. The varied age and canopy structure of woodland encourages a high diversity of butterflies, nationally scarce species including the white-letter hairstreak Satyrium w-album and high brown fritillary Argynnis adippe, while species such as the chalkhill blue Polyommatus coridon and brown argus Aricia agestis occur on the limestone grassland. Greater horseshoe bats Rhinolophus ferrumequinum and lesser horseshoes Rhinolophus hipposideros regularly use sites in the Gorge as hibernacular roosts. Several caves occur within the Gorge, of which Bridged Pot provides one of the best presumed Late Devensian small mammal assemblages known from Britain. Most of the deposit remains in situ. The fauna includes steppe pika, arctic lemming, Norway lemming, various voles, red deer and reindeer. The small cave/rock shelter at Savoy's Hole contains largely undisturbed deposits likely to yield a similar assemblage of Devensian age.

Species mentioned

English name
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Latin name
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IUCN / Red List Type Family
greater horseshoe bat Rhinolophus ferrumequinum LC bat vespertillonidae
lesser horseshoe bat Rhinolophus hipposideros LC bat vespertillonidae
brown argus Aricia agestis LC butterfly lycaenidae
chalkhill blue Polyommatus coridon VU butterfly lycaenidae
white-letter hairstreak Satyrium w-album VU butterfly lycaenidae
quaking grass Briza media VU grass poaceae
moschatel Adoxa moschatellina LC herb adoxaceae
wood anemone Anemone nemorosa LC herb ranunculaceae
carline thistle Carlina vulgaris LC herb asteraceae
opposite-leaved golden- saxifrage Chrysosplenium oppositifolium LC herb saxifragaceae
pignut Conopodium majus LC herb apiaceae
rock roses Helianthemum nummularium VU herb cistaceae
bluebell Hyacinthoides non-scripta LC herb liliaceae
fairy flax Linum catharticum LC herb linaceae
dog's mercury Mercurialis perennis LC herb euphorbiaceae
wild marjoram Origanum vulgare LC herb lamiaceae
common milkwort Polygala vulgaris VU herb polygalaceae
salad burnet Poterium sanguisorba VU herb rosaceae
primrose Primula vulgaris LC herb primulaceae
sanicle Sanicula europaea LC herb apiaceae
wild thyme Thymus polytrichus Not listed in GB list herb lamiaceae
tiny feather moss Amblystegium confervoides Not listed in GB list moss hypnales
thread moss Bryum canariense LC moss bryales
wood sedge Carex sylvatica LC sedge cyperaceae
dogwood Cornus sanguinea LC shrub cornaceae
spindle tree Euonymus europaeus LC shrub celastraceae
wild privet Ligustrum vulgare LC shrub oleaceae
gorse Ulex europaeus LC shrub leguminosae
wayfaring tree Viburnum lantana LC shrub caprifoliaceae
gelder rose Viburnum opulus LC shrub caprifoliaceae
bell heather Erica cinerea NT shrub dwarf ericaceae
field maple Acer campestre LC tree aceraceae
hornbeam Carpinus betulus LC tree betulaceae
hazel Corylus avellana LC tree corylaceae
beech Fagus sylvatica LC tree fabiaceae
ash Fraxinus excelsior LC tree oleaceae
common oak Quercus robur LC tree fagaceae

Insects to look out for

These moths, butterflies and beetles are known to feed on plants recorded at this site, and carry a notable UK conservation status — but a host-plant being present doesn't mean the insect has actually been recorded here. Treat this as "worth watching for," not a confirmed sighting.

SpeciesStatusVia host-plant
Black-veined moth
Siona lineata
Critically Endangered Origanum vulgare
Straw belle
Aspitates gilvaria
Endangered Linum catharticum
Oak lutestring
Cymatophorina diluta
Endangered Quercus robur
Maple pug
Eupithecia inturbata
Endangered Acer campestre
Duke of Burgundy
Hamearis lucina
Endangered Primula vulgaris
Shoulder-striped clover
Heliothis maritima
Endangered Erica cinerea
Scarce vapourer
Orgyia recens
Endangered Corylus avellana, Fagus sylvatica, Quercus spp.
Mouse moth
Amphipyra tragopoginis
Vulnerable Poterium sanguisorba
Northern brown
Aricia artaxerxes
Vulnerable Helianthemum nummularium
The sprawler
Asteroscopus sphinx
Vulnerable Corylus avellana, Fagus sylvatica, Fraxinus excelsior, Quercus spp., Viburnum lantana
Mottled umber
Erannis defoliaria
Vulnerable Acer campestre, Carpinus betulus, Corylus avellana, Fagus sylvatica, Quercus spp.
Satyr pug
Eupithecia satyrata
Vulnerable Helianthemum nummularium
True lover's knot
Lycophotia porphyrea
Vulnerable Erica cinerea
The lackey
Malacosoma neustria
Vulnerable Corylus avellana, Quercus spp.
Pale brindled
Phigalia pilosaria
Vulnerable Cornus sanguinea, Corylus avellana, Fraxinus excelsior, Quercus spp.
Silver studded blue
Plebejus argus
Vulnerable Erica cinerea, Helianthemum nummularium, Ulex spp.
Grizzled skipper
Pyrgus malvae
Vulnerable Poterium sanguisorba
Lead belle
Scotopteryx mucronata
Vulnerable Ulex europaeus
Early moth
Theria primaria
Vulnerable Quercus spp.
Pale eggar
Trichiura crataegi
Vulnerable Corylus avellana, Erica cinerea, Quercus spp.
Oak hook-tip
Watsonalla binaria
Vulnerable Quercus robur
Flounced chestnut
Agrochola helvola
Near Threatened Quercus spp.
Light crimson underwing
Catocala promissa
Near Threatened Quercus robur
Dark crimson underwing
Catocala sponsa
Near Threatened Quercus robur
Heart moth
Dicycla oo
Near Threatened Quercus robur
Grey scalloped
Dyscia fagaria
Near Threatened Erica cinerea
Large thorn
Ennomos autumnaria
Near Threatened Corylus avellana, Quercus spp.
September thorn
Ennomos erosaria
Near Threatened Fagus sylvatica, Quercus spp.
Dusky thorn
Ennomos fuscantaria
Near Threatened Fraxinus excelsior
Autumnal rustic
Eugnorisma glareosa
Near Threatened Erica cinerea, Hyacinthoides non-scripta
Double dart
Graphiphora augur
Near Threatened Quercus spp.
Silky wave
Idaea dilutaria
Near Threatened Helianthemum nummularium
Clay fan-foot
Paracolax tristalis
Near Threatened Quercus spp.
Common fan-foot
Pechipogo strigilata
Near Threatened Quercus robur
Frosted green
Polyploca ridens
Near Threatened Quercus robur

Host-plant data: Cook et al. (2025), Traits data for the butterflies and macro-moths of Great Britain and Ireland, 2024, UK Centre for Ecology & Hydrology / Butterfly Conservation; and Padovani et al. (2020), Database of Insects and their Food Plants (DBIF), UK Centre for Ecology & Hydrology (both Open Government Licence). Contains data supplied by UK Centre for Ecology & Hydrology.

Plant communities

A14 — Fast flowing river and stream

Myriophyllum alterniflorum community

Isolepis fluitans, Juncus bulbosus, Fontinalis antipyretica, Lobelia dortmanna, Equisetum fluviatile, Myriophyllum alterniflorum, Lemna minor, Callitriche stagnalis, Littorella uniflora, Potamogeton filiformis, Potamogeton gramineus, Potamogeton natans, Ranunculus peltatus, Chara spp., Nitella hyalina

A17 — Chalk river and stream, Fast flowing river and stream

Ranunculus penicillatus ssp. pseudofluitans community

Berula erecta, Nasturtium officinale, Elodea canadensis, Lemna minor, Callitriche stagnalis, Veronica beccabunga, Polygonum amphibium, Polygonum hydropiper, Potamogeton crispus, Potamogeton pectinatus, Ranunculus penicillatus ssp. pseudofluitans

A18 — Fast flowing river and stream

Ranunculus fluitans community

Fontinalis antipyretica, Fontinalis squamosa var. curnowii, Myriophyllum alterniflorum, Myriophyllum spicatum, Elodea canadensis, Mentha aquatica, Lemna gibba, Lemna minor, Potamogeton perfoliatus, Ranunculus fluitans, Glyceria fluitans, Phalaris arundinacea

A9 — Fast flowing river and stream, Marginal and inundation, Pond ditch and canal, Sluggish river and stream

Potamogeton natans community

Schoenoplectus lacustris, Juncus bulbosus, Sparganium angustifolium, Sparganium erectum, Sparganium minimum, Alisma plantago-aquatica, Lobelia dortmanna, Equisetum fluviatile, Myriophyllum alterniflorum, Elodea canadensis, Lemna minor, Lemna trisulca, Nymphaea alba, Callitriche platycarpa, Callitriche stagnalis, Littorella uniflora, Potamogeton natans, Ranunculus trichophyllus, Glyceria fluitans, Chara subspinosa