Sugar Loaf Woodlands

Site of Special Scientific Interest · 51.8468, -3.0376

Geology & landscape

Rock Type: Sandstone

Description

Description Three extensive areas of ancient coppice woodland (St Mary’s Vale, Twyn-yr-Allt and The Park) on the south and east slopes of the Sugar Loaf Mountain on Brownstones of the Old Red Sandstone Series. Most of the woodland is dominated by sessile oak Quercus petraea which gives way to pedunculate oak Q robur and hybrids on the lower slopes. Local areas of alder Alnus glutinosa and beech Fagus sylvatica occur alongside streams. There is a characteristic acidopholous ground flora with large areas dominated by bilberry Vaccinium myrtillus and wavy hairgrass Deschampsia flexuosa which changes to more luxuriant herb, fern and bryophyte communities on the flushed lower slopes and streamsides. Epiphytic lichens are abundant, particularly on the trees of the upper slopes. Remarks: Within Brecon Beacons National Park.

Species mentioned

English name
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Latin name
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IUCN / Red List Type Family
wavy hair grass Deschampsia flexuosa Not listed in GB list grass poaceae
billberry Vaccinium myrtillus LC shrub ericaceae
alder Alnus glutinosa LC tree salicaceae
beech Fagus sylvatica LC tree fabiaceae
sessile or durmast oak Quercus petraea 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
Speckled footman
Coscinia cribraria
Critically Endangered Vaccinium myrtillus
Oak lutestring
Cymatophorina diluta
Endangered Quercus petraea
Scarce vapourer
Orgyia recens
Endangered Alnus glutinosa, Fagus sylvatica, Quercus spp.
The sprawler
Asteroscopus sphinx
Vulnerable Fagus sylvatica, Quercus spp.
Broom moth
Ceramica pisi
Vulnerable Vaccinium myrtillus
Mottled umber
Erannis defoliaria
Vulnerable Fagus sylvatica, Quercus spp., Vaccinium myrtillus
The lackey
Malacosoma neustria
Vulnerable Quercus spp.
Pale brindled
Phigalia pilosaria
Vulnerable Alnus glutinosa, Quercus spp.
Early moth
Theria primaria
Vulnerable Quercus spp., Vaccinium myrtillus
Pale eggar
Trichiura crataegi
Vulnerable Quercus spp., Vaccinium myrtillus
Oak hook-tip
Watsonalla binaria
Vulnerable Quercus petraea
Flounced chestnut
Agrochola helvola
Near Threatened Quercus spp., Vaccinium myrtillus
Beaded chestnut
Agrochola lychnidis
Near Threatened Vaccinium myrtillus
Rosy marsh moth
Coenophila subrosea
Near Threatened Vaccinium myrtillus
Dingy mocha
Cyclophora pendularia
Near Threatened Alnus glutinosa
Kentish glory
Endromis versicolora
Near Threatened Alnus glutinosa
Large thorn
Ennomos autumnaria
Near Threatened Alnus glutinosa, Quercus spp.
September thorn
Ennomos erosaria
Near Threatened Fagus sylvatica, Quercus spp.
The Silurian
Eriopygodes imbecilla
Near Threatened Vaccinium myrtillus
Double dart
Graphiphora augur
Near Threatened Quercus spp.
Clay fan-foot
Paracolax tristalis
Near Threatened Quercus spp.
Frosted green
Polyploca ridens
Near Threatened Quercus petraea
Scotch burnet
Zygaena exulans
Near Threatened Vaccinium myrtillus

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.