Caer Llan Wood

Site of Special Scientific Interest · 51.7683, -2.7346

Geology & landscape

Geological Feature: Gorge / Ravine · Rock Type: Conglomerate, Limestone, Sandstone

Landscape processes: Fluvial

Description

Description The woodlands of the lower Wye Valley form one of the most important areas for woodland nature conservation in Britain, comparable with the Caledonian pinewoods, the oceanic oakwoods of western Britain, the New Forest and the mixed coppices of East Anglia. Unlike most other regions, semi-natural woodland is abundant and virtually continuous along the gorge. The woods are a mixture of many types, some of which are localised, e.g., the lime-sessile oak stands on limestone; beech stands on both acid and alkaline soils in which lime, elm, oak and other species share dominance. Most woods are a rich mixture of stand types, which are believed to be similar in composition to the original natural woods of the valley. Many rare and local species are present, including some of the rarest native tree species (E.G. large-leaved lime, whitebeams), and trees close to the edge of their northern European range, e.g., hornbeam, beech. Furthermore, these woods sit in a matrix of unimproved grassland and other semi-natural habitats which, together with the woods, make the Wye Valley one of the most diverse, rich and attractive areas of southern Britain. Caer Llan Wood is an area with several woodland types and transitions on Old Red Sandstone Quartz Conglomerate. The upper slopes are dominated by pedunculate oak Quercus robur and the lower slopes by wych elm Ulmus glabra, both as standards and areas of relict coppice. Examples of this upland pedunculate oak woodland type on acidic soils are rare in the County. Remarks: Within the Wye Valley Area of Outstanding Natural Beauty.

Species mentioned

English name
search for this in other sites
Latin name
search with Google
IUCN / Red List Type Family
common oak Quercus robur LC tree fagaceae
wych elm Ulmus glabra LC tree ulmaceae

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
Oak lutestring
Cymatophorina diluta
Endangered Quercus robur
Scarce vapourer
Orgyia recens
Endangered Quercus spp., Ulmus spp.
White-letter hairstreak
Satyrium w-album
Endangered Ulmus glabra, Ulmus spp.
The sprawler
Asteroscopus sphinx
Vulnerable Quercus spp., Ulmus spp.
Broom moth
Ceramica pisi
Vulnerable Ulmus spp.
Mottled umber
Erannis defoliaria
Vulnerable Quercus spp., Ulmus spp.
The lackey
Malacosoma neustria
Vulnerable Quercus spp., Ulmus spp.
Pale brindled
Phigalia pilosaria
Vulnerable Quercus spp., Ulmus glabra
Early moth
Theria primaria
Vulnerable Quercus spp.
Pale eggar
Trichiura crataegi
Vulnerable Quercus spp.
Oak hook-tip
Watsonalla binaria
Vulnerable Quercus robur
Flounced chestnut
Agrochola helvola
Near Threatened Quercus spp., Ulmus spp.
Light crimson underwing
Catocala promissa
Near Threatened Quercus robur
Dark crimson underwing
Catocala sponsa
Near Threatened Quercus robur
Dusky-lemon sallow
Cirrhia gilvago
Near Threatened Ulmus glabra
The sallow
Cirrhia icteritia
Near Threatened Ulmus glabra
Heart moth
Dicycla oo
Near Threatened Quercus robur
Large thorn
Ennomos autumnaria
Near Threatened Quercus spp., Ulmus spp.
September thorn
Ennomos erosaria
Near Threatened Quercus spp.
Double dart
Graphiphora augur
Near Threatened Quercus spp., Ulmus spp.
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.